Deleterious effects of recombination and possible
... fruiting initials carrying the fittest dikaryons. Eventually, the proliferated dikaryotic cells undergo nuclear fusion (karyogamy) forming as many identical diploid zygotes that do not divide but directly undergo meiosis, followed by a mitotic division resulting in eight haploid meiotic spores (call ...
... fruiting initials carrying the fittest dikaryons. Eventually, the proliferated dikaryotic cells undergo nuclear fusion (karyogamy) forming as many identical diploid zygotes that do not divide but directly undergo meiosis, followed by a mitotic division resulting in eight haploid meiotic spores (call ...
File
... The gills are 2 white feathery structures found within the mantle cavity. Squid actually have 3 hearts! Each of these hearts is quite small and slightly yellowish in color. At the base of each gill is a branchial heart (also called the gill heart) which pumps blood from the body up to the gills to b ...
... The gills are 2 white feathery structures found within the mantle cavity. Squid actually have 3 hearts! Each of these hearts is quite small and slightly yellowish in color. At the base of each gill is a branchial heart (also called the gill heart) which pumps blood from the body up to the gills to b ...
Bacteria and Viruses
... host cell. The virus attaches to the host cell using specific receptors on the plasma ...
... host cell. The virus attaches to the host cell using specific receptors on the plasma ...
developmental biology 5 fertilization Introduction: Special features of
... surrounding unfertilized sea urchin eggs), agglutinated the sperm and activated their motility. The reaction was species specific. This factor called fertilizin came from the egg jelly coat. It slowly dissolved as in sea water. Fertilizin was later shown to be the constituent of both jelly coat and ...
... surrounding unfertilized sea urchin eggs), agglutinated the sperm and activated their motility. The reaction was species specific. This factor called fertilizin came from the egg jelly coat. It slowly dissolved as in sea water. Fertilizin was later shown to be the constituent of both jelly coat and ...
DEVELOPMENTAL BIOLOGY 5 FERTILIZATION
... surrounding unfertilized sea urchin eggs), agglutinated the sperm and activated their motility. The reaction was species specific. This factor called fertilizin came from the egg jelly coat. It slowly dissolved as in sea water. Fertilizin was later shown to be the constituent of both jelly coat and ...
... surrounding unfertilized sea urchin eggs), agglutinated the sperm and activated their motility. The reaction was species specific. This factor called fertilizin came from the egg jelly coat. It slowly dissolved as in sea water. Fertilizin was later shown to be the constituent of both jelly coat and ...
Sex hormones and finger length: What
... upcoming ‘‘dating game’’ when they made their baseline recording; thus this knowledge may have influenced acoustic parameters of their voices. After this dating game scenario, each subject was given a questionnaire designed to assess social and physical dominance, sociosexuality, sexual interest in ...
... upcoming ‘‘dating game’’ when they made their baseline recording; thus this knowledge may have influenced acoustic parameters of their voices. After this dating game scenario, each subject was given a questionnaire designed to assess social and physical dominance, sociosexuality, sexual interest in ...
The Cultural Production of English Masculinities in Late Modernity
... using the concept of “investment” to refer to a process of making the self, examined why individual heterosexual men invest in one rather than another. She suggests that investments signal affiliation with subject positions that bring rewards. This investment is not always conscious: It may be subme ...
... using the concept of “investment” to refer to a process of making the self, examined why individual heterosexual men invest in one rather than another. She suggests that investments signal affiliation with subject positions that bring rewards. This investment is not always conscious: It may be subme ...
alignment coital picture technique
... factors. The sexual problem may arise as a result of disease, surgery, medication, or psychological factors, and depending upon the age of the patient, may be confounded with normal age-related declines in sexual functioning [29 .]. It is important that studies examining the relationship between med ...
... factors. The sexual problem may arise as a result of disease, surgery, medication, or psychological factors, and depending upon the age of the patient, may be confounded with normal age-related declines in sexual functioning [29 .]. It is important that studies examining the relationship between med ...
The Worms - Cloudfront.net
... Tapeworms The largest tapeworms can grow up to 58ft long You can become contaminated by eating infected food They harm what they are living in by stealing vital nutrients. (House episode) ...
... Tapeworms The largest tapeworms can grow up to 58ft long You can become contaminated by eating infected food They harm what they are living in by stealing vital nutrients. (House episode) ...
Final Exam - Salinella
... ________ 3.1 In insects, the circulatory system picks up oxygen from the tiny air sacs at the end of the tracheoles and carries the oxygen through the blood to all tissues. ________ 3.2 The body surface of an earthworm is kept moist by mucus and excretory fluid so that gas exchange can occur across ...
... ________ 3.1 In insects, the circulatory system picks up oxygen from the tiny air sacs at the end of the tracheoles and carries the oxygen through the blood to all tissues. ________ 3.2 The body surface of an earthworm is kept moist by mucus and excretory fluid so that gas exchange can occur across ...
Precis of `The Mating Mind` By Geoffrey Miller Published as: Miller
... selection because such models assumed fitness would remain heritable across many generations. Yet Fisher's (1930) 'fundamental theorem of natural selection' implied that selection should decrease genetic variance, driving disfavoured alleles to extinction, thereby decreasing the heritability of fitn ...
... selection because such models assumed fitness would remain heritable across many generations. Yet Fisher's (1930) 'fundamental theorem of natural selection' implied that selection should decrease genetic variance, driving disfavoured alleles to extinction, thereby decreasing the heritability of fitn ...
Same-sex sexual behavior and evolution
... affect pheromone receptors (Box 1). Sex-specific pheromones and their accurate detection are crucial for sex recognition in fruit flies, and alterations in sex-recognition pathways can produce males that court other males, females that court females, or males that switch from same-sex to opposite-se ...
... affect pheromone receptors (Box 1). Sex-specific pheromones and their accurate detection are crucial for sex recognition in fruit flies, and alterations in sex-recognition pathways can produce males that court other males, females that court females, or males that switch from same-sex to opposite-se ...
Functioning organisms
... fruit in positions where they can function effectively. Stems contain tube-like vascular bundles through which water and mineral nutrients travel up from the soil to the leaves and glucose solutions travel to the cells throughout the plant. Some stems also can carry out photosynthesis, the foodmakin ...
... fruit in positions where they can function effectively. Stems contain tube-like vascular bundles through which water and mineral nutrients travel up from the soil to the leaves and glucose solutions travel to the cells throughout the plant. Some stems also can carry out photosynthesis, the foodmakin ...
Life at Its Many Levels
... Compare the structure of prokaryotic and eukaryotic cells. Distinguish between the three domains and four eukaryotic kingdoms of life. Describe the two main points that Darwin makes in The Origin of Species. Describe the two observations that led Darwin to his inescapable conclusion. State this ...
... Compare the structure of prokaryotic and eukaryotic cells. Distinguish between the three domains and four eukaryotic kingdoms of life. Describe the two main points that Darwin makes in The Origin of Species. Describe the two observations that led Darwin to his inescapable conclusion. State this ...
Same-sex sexual behavior and evolution Nathan W. Bailey and Marlene Zuk Review
... affect pheromone receptors (Box 1). Sex-specific pheromones and their accurate detection are crucial for sex recognition in fruit flies, and alterations in sex-recognition pathways can produce males that court other males, females that court females, or males that switch from same-sex to opposite-se ...
... affect pheromone receptors (Box 1). Sex-specific pheromones and their accurate detection are crucial for sex recognition in fruit flies, and alterations in sex-recognition pathways can produce males that court other males, females that court females, or males that switch from same-sex to opposite-se ...
Same-sex sexual behavior and evolution
... affect pheromone receptors (Box 1). Sex-specific pheromones and their accurate detection are crucial for sex recognition in fruit flies, and alterations in sex-recognition pathways can produce males that court other males, females that court females, or males that switch from same-sex to opposite-se ...
... affect pheromone receptors (Box 1). Sex-specific pheromones and their accurate detection are crucial for sex recognition in fruit flies, and alterations in sex-recognition pathways can produce males that court other males, females that court females, or males that switch from same-sex to opposite-se ...
Paedophilia : therapeutic issues
... Research has established that the beliefs also are not always correct. Hence most offenders must at times have had experiences when child abuse did not produce harm or the child initiated sexual activity. Rather than force offenders to pretend to believe what they know to be false, the occasional re ...
... Research has established that the beliefs also are not always correct. Hence most offenders must at times have had experiences when child abuse did not produce harm or the child initiated sexual activity. Rather than force offenders to pretend to believe what they know to be false, the occasional re ...
reproductive options for trans people
... Success rates for assisted human reproductive (AHR) services vary. A French study from 1989 found that 50% of the cis women using frozen sperm had conceived within 6 months of treatment cycles.(32) A recent study at the Mayo Clinic found that in terms of pregnancy rates and live births there was no ...
... Success rates for assisted human reproductive (AHR) services vary. A French study from 1989 found that 50% of the cis women using frozen sperm had conceived within 6 months of treatment cycles.(32) A recent study at the Mayo Clinic found that in terms of pregnancy rates and live births there was no ...
The Cnidarians and Flatworms Laboratory
... medusa. Medusae are free-swimming and are best described as being shaped like an umbrella or bell. Reproduction in cnidarians can include sexual and asexual stages. Gonads develop in the epidermal tissue and release gametes into the water directly for external fertilization. A form of asexual reprod ...
... medusa. Medusae are free-swimming and are best described as being shaped like an umbrella or bell. Reproduction in cnidarians can include sexual and asexual stages. Gonads develop in the epidermal tissue and release gametes into the water directly for external fertilization. A form of asexual reprod ...
the classification of living organisms
... Living organisms can be grouped according to the things that they have in common. Classification is sorting living organisms into groups, based on their similarities. Living organisms are sorted and classified according to characteristics that they share. Early-day classification systems were based ...
... Living organisms can be grouped according to the things that they have in common. Classification is sorting living organisms into groups, based on their similarities. Living organisms are sorted and classified according to characteristics that they share. Early-day classification systems were based ...
File - Down the Rabbit Hole
... that even though the gastrocoel functions like stomach, it can’t be called that because it has only one opening. ...
... that even though the gastrocoel functions like stomach, it can’t be called that because it has only one opening. ...
Extramarital Sex/Infidelity
... Researchers have struggled to accurately assess the occurrence of infidelity among married and non-married couples. Research results on lifetime incidence rates of extramarital sex have shown great inconsistency, with findings and estimates ranging from rates as low as 1.5 to as high as 50 percent. ...
... Researchers have struggled to accurately assess the occurrence of infidelity among married and non-married couples. Research results on lifetime incidence rates of extramarital sex have shown great inconsistency, with findings and estimates ranging from rates as low as 1.5 to as high as 50 percent. ...
Influence of Body Size and Population Density on
... Two-way ANOVA of arcsine transformed data (percent fertilization). Factors were male density and male body size. ...
... Two-way ANOVA of arcsine transformed data (percent fertilization). Factors were male density and male body size. ...
PDF
... activated. Before birth, the researchers report, BDNF activates the transcription factor NF-κB by an atypical mechanism that involves tyrosine phosphorylation of the inhibitor IκBα by Src family kinases and its subsequent dissociation from NF-κB. At this developmental time, BDNF also dephosphorylate ...
... activated. Before birth, the researchers report, BDNF activates the transcription factor NF-κB by an atypical mechanism that involves tyrosine phosphorylation of the inhibitor IκBα by Src family kinases and its subsequent dissociation from NF-κB. At this developmental time, BDNF also dephosphorylate ...
Sexual reproduction
Sexual reproduction is a form of reproduction where two morphologically distinct types of specialized reproductive cells called gametes fuse together, involving a female's large ovum (or egg) and a male's smaller sperm. Each gamete contains half the number of chromosomes of normal cells. They are created by a specialized type of cell division, which only occurs in eukaryotic cells, known as meiosis. The two gametes fuse during fertilization to produce DNA replication and the creation of a single-celled zygote which includes genetic material from both gametes. In a process called genetic recombination, genetic material (DNA) joins up so that homologous chromosome sequences are aligned with each other, and this is followed by exchange of genetic information. Two rounds of cell division then produce four daughter cells with half the number of chromosomes from each original parent cell, and the same number of chromosomes as both parents, though self-fertilization can occur. For instance, in human reproduction each human cell contains 46 chromosomes, 23 pairs, except gamete cells, which only contain 23 chromosomes, so the child will have 23 chromosomes from each parent genetically recombined into 23 pairs. Cell division initiates the development of a new individual organism in multicellular organisms, including animals and plants, for the vast majority of whom this is the primary method of reproduction. A species is defined as a taxonomic rank. A species is often defined as the largest group of organisms where two hybrids are capable of reproducing fertile offspring, typically using sexual reproduction, although the species problem encompasses a series of difficult related questions that often come up when biologists define the word species. The evolution of sexual reproduction is a major puzzle because asexual reproduction should be able to outcompete it as every young organism created can bear its own young. This implies that an asexual population has an intrinsic capacity to grow more rapidly with each generation. This 50% cost is a fitness disadvantage of sexual reproduction. The two-fold cost of sex includes this cost and the fact that any organism can only pass on 50% of its own genes to its offspring. One definite advantage of sexual reproduction is that it prevents the accumulation of genetic mutations.Sexual selection is a mode of natural selection in which some individuals out-reproduce others of a population because they are better at securing mates for sexual reproduction. It has been described as ""a powerful evolutionary force that does not exist in asexual populations""Prokaryotes reproduce through asexual reproduction but may display processes similar to sexual reproduction (mechanisms for lateral gene transfer such as bacterial conjugation, transformation and transduction), but they do not lead to reproduction. In prokaryotes, the initial cell has additional or transformed genetic material.