Sperm competition and sperm cooperation: the potential role of
... expression. If we exclude the potential influence of the male for now, and assume that haploid gene expression is unlimited, sperm cooperation may evolve with the same likelihood as the cooperation between full siblings (Hamilton 1964). The reason for this is that sibling sperm share 50% of their ge ...
... expression. If we exclude the potential influence of the male for now, and assume that haploid gene expression is unlimited, sperm cooperation may evolve with the same likelihood as the cooperation between full siblings (Hamilton 1964). The reason for this is that sibling sperm share 50% of their ge ...
Fertilization - Formatted
... discharged in the aquatic medium and the fertilization occurs outside the body of both male and female parents, as in most invertebrates and some vertebrates (fish and frog). The aquatic medium for external fertilization may be either seawater or fresh water. When fertilization occurs inside the bod ...
... discharged in the aquatic medium and the fertilization occurs outside the body of both male and female parents, as in most invertebrates and some vertebrates (fish and frog). The aquatic medium for external fertilization may be either seawater or fresh water. When fertilization occurs inside the bod ...
Effect of cooling and freezing, the two first steps
... for 6 or 8 h at 5 ºC before being used for insemination; the percentage of does kidding was 67%, with 6.5 rabbits/female kidding, but no females were inseminated with fresh sperm for comparison. Maurer et al. [9], used the same extender as Stranzinger et al. [18], and they compared the results for s ...
... for 6 or 8 h at 5 ºC before being used for insemination; the percentage of does kidding was 67%, with 6.5 rabbits/female kidding, but no females were inseminated with fresh sperm for comparison. Maurer et al. [9], used the same extender as Stranzinger et al. [18], and they compared the results for s ...
Why do sperm carry RNA? Relatedness, conflict
... genotype [36]. Hence, there is potential for directly displaying attributes that signal relatedness or shared genes, and differences in miRNA expression are associated with different sperm phenotypes [9]; thus, it is plausible that sperm phenotypes could reveal information about sperm relatedness. C ...
... genotype [36]. Hence, there is potential for directly displaying attributes that signal relatedness or shared genes, and differences in miRNA expression are associated with different sperm phenotypes [9]; thus, it is plausible that sperm phenotypes could reveal information about sperm relatedness. C ...
corals - Natural History Museum
... (Phylums) called the Cnidaria. Soft-bodied sea anemones and jellyfish decay quickly after death which prevents fossilisation except under unusual circumstance. Corals, however, have a long geological history due to their hard skeleton which remains after the soft polyp body has decayed. Today, such ...
... (Phylums) called the Cnidaria. Soft-bodied sea anemones and jellyfish decay quickly after death which prevents fossilisation except under unusual circumstance. Corals, however, have a long geological history due to their hard skeleton which remains after the soft polyp body has decayed. Today, such ...
Microtus ochrogaster
... Microtus ochrogaster is a crepuscular mammal. Activity occurs during sunrise and sunset, although activity changes throughout the seasons. Diurnal activity decreases during summer, and increase during the winter. Communal groups that are formed, are usually made of offspring and survivors from the ...
... Microtus ochrogaster is a crepuscular mammal. Activity occurs during sunrise and sunset, although activity changes throughout the seasons. Diurnal activity decreases during summer, and increase during the winter. Communal groups that are formed, are usually made of offspring and survivors from the ...
The use of uterine scars to explore fecundity levels in invasive alien
... and Hammershøj, 2006). Even in our case, preliminary trials on individuals that gave birth during summer did not evidence any scars if stained after winter diapause, indicating that after winter the process of endometrium repair is completed and uterine scars can no longer be revealed by our stainin ...
... and Hammershøj, 2006). Even in our case, preliminary trials on individuals that gave birth during summer did not evidence any scars if stained after winter diapause, indicating that after winter the process of endometrium repair is completed and uterine scars can no longer be revealed by our stainin ...
Document
... Results: In this study we used two different in vitro fertilization experiments to assess how fast eggs are fertilized in sticklebacks. We show that complete fertilization takes more than 5 min which is atypically long for externally fertilizing fishes. Conclusion: This result suggests that the time ...
... Results: In this study we used two different in vitro fertilization experiments to assess how fast eggs are fertilized in sticklebacks. We show that complete fertilization takes more than 5 min which is atypically long for externally fertilizing fishes. Conclusion: This result suggests that the time ...
Seasonal Timing of Reproduction and Hibernation in the Edible
... Dormice are nocturnal inhabitants of deciduous forests with an adult body mass of 100–130 g after emergence from hibernation (Bieber, 1998). In spite of their strong arboreal life during the active season, dormice hibernate underground at a depth of 30–80 cm (Vietinghoff-Riesch, 1960). At our study ...
... Dormice are nocturnal inhabitants of deciduous forests with an adult body mass of 100–130 g after emergence from hibernation (Bieber, 1998). In spite of their strong arboreal life during the active season, dormice hibernate underground at a depth of 30–80 cm (Vietinghoff-Riesch, 1960). At our study ...
GUINEA PIGS FOR MEAT PRODUCTION
... 140 g (1.5-5 ounces), are fully developed, can see, smell, walk, run, eat all but hard foods, and even survive without the mother if necessary. Nevertheless, they grow more rapidly if kept with the mother for 2-3 weeks. The young are sometimes accidentally injured or, less frequently, killed by both ...
... 140 g (1.5-5 ounces), are fully developed, can see, smell, walk, run, eat all but hard foods, and even survive without the mother if necessary. Nevertheless, they grow more rapidly if kept with the mother for 2-3 weeks. The young are sometimes accidentally injured or, less frequently, killed by both ...
Reproductive versus ecological advantages to larger body size in
... without major modifications of the habitat exploited, either in terms of space (e.g., no great variation in predatory pressures or diet) or time (e.g., seasons). Such a situation will allow us to explore the consequences of body-size variation independently for these two major categories of selectiv ...
... without major modifications of the habitat exploited, either in terms of space (e.g., no great variation in predatory pressures or diet) or time (e.g., seasons). Such a situation will allow us to explore the consequences of body-size variation independently for these two major categories of selectiv ...
REPRODUCTION - Teaching Biology Project
... Males and females find suitable mates e.g. male with best genetic potential. ...
... Males and females find suitable mates e.g. male with best genetic potential. ...
reproduction - Teaching Biology Project
... Males and females find suitable mates e.g. male with best genetic potential. ...
... Males and females find suitable mates e.g. male with best genetic potential. ...
Asexual reproduction - Wikipedia, the free encyclopedia
... citrus seeds. Male apomixis can occur in rare cases, such as the Saharan Cypress Cupressus dupreziana, where the genetic material of the embryo are derived entirely from pollen. The term "apomixis" is also used for asexual reproduction in some animals, notably water-fleas, Daphnia. ...
... citrus seeds. Male apomixis can occur in rare cases, such as the Saharan Cypress Cupressus dupreziana, where the genetic material of the embryo are derived entirely from pollen. The term "apomixis" is also used for asexual reproduction in some animals, notably water-fleas, Daphnia. ...
spider monkey fact sheet - World Animal Foundation
... supervision and mental stimulation. They usually require a large amount of attention. Monkeys cannot handle being away from their owners for long periods of time, such as family trips for example, due to their need of attention. Bored monkeys can become extremely destructive and may even go so far a ...
... supervision and mental stimulation. They usually require a large amount of attention. Monkeys cannot handle being away from their owners for long periods of time, such as family trips for example, due to their need of attention. Bored monkeys can become extremely destructive and may even go so far a ...
The Primates of Sri Lanka
... which can be studied through observations in sites with public access without the onerous requirement of research permits. We hope this book will inspire both professional scientists and enthusiasts to pursue the scientific study of the island’s biodiversity. We also hope that the general public wil ...
... which can be studied through observations in sites with public access without the onerous requirement of research permits. We hope this book will inspire both professional scientists and enthusiasts to pursue the scientific study of the island’s biodiversity. We also hope that the general public wil ...
Chapter-12
... • Variation in the forms and combinations of heritable traits diversity • Increase chance of surviving in a changing environment ...
... • Variation in the forms and combinations of heritable traits diversity • Increase chance of surviving in a changing environment ...
Reproduction - Male
... Transmission of nutrients from dam to young. Transmission of wastes from young to dam. Protection of young from shock and adhesions by means of Amniotic Fluid. Prevention of bacteria and other large molecular substances from dam to young. The secretion of certain hormones; HCG (woman) and PMSG (mare ...
... Transmission of nutrients from dam to young. Transmission of wastes from young to dam. Protection of young from shock and adhesions by means of Amniotic Fluid. Prevention of bacteria and other large molecular substances from dam to young. The secretion of certain hormones; HCG (woman) and PMSG (mare ...
Long-Tailed Weasel - Vermont Fish and Wildlife
... slim body, long neck and short legs. It is very agile and fast when on the move, slinking along in an up and down fashion. The tail is brown with a black tip. The long-tailed weasel's coat changes color with the seasons. It is dark brown to red in the summer with lighter underparts and dark feet. In ...
... slim body, long neck and short legs. It is very agile and fast when on the move, slinking along in an up and down fashion. The tail is brown with a black tip. The long-tailed weasel's coat changes color with the seasons. It is dark brown to red in the summer with lighter underparts and dark feet. In ...
Sperm Concentrations and Egg Fertilization Rates
... the first day, 50 I.U. of human chorionic gonadotropin, was given to all fish. On the following day, all fish were squeezed, and males were identified by the secretion of milt. Fish that did not secrete milt when squeezed were assumed to be females and given the second injection. The number of males ...
... the first day, 50 I.U. of human chorionic gonadotropin, was given to all fish. On the following day, all fish were squeezed, and males were identified by the secretion of milt. Fish that did not secrete milt when squeezed were assumed to be females and given the second injection. The number of males ...
What is the appropriate timescale for measuring
... body condition at the ®rst capture (indicating that they were not post-parturient: e.g. absence of ¯accid abdomen or extensive skin folds), and they needed to have been regularly recaptured (so that we were sure that they did not produce a litter during this period). Some of them were ®rst caught as ...
... body condition at the ®rst capture (indicating that they were not post-parturient: e.g. absence of ¯accid abdomen or extensive skin folds), and they needed to have been regularly recaptured (so that we were sure that they did not produce a litter during this period). Some of them were ®rst caught as ...
Life Science: Session 4
... Sexual reproduction and the unique process known as alternation of generations characterize the life cycles of plants. Other strategies for reproducing can also be observed in plants — strategies that don’t involve the union of sperm and egg. These strategies involve asexual reproduction, where one ...
... Sexual reproduction and the unique process known as alternation of generations characterize the life cycles of plants. Other strategies for reproducing can also be observed in plants — strategies that don’t involve the union of sperm and egg. These strategies involve asexual reproduction, where one ...
Animal sexual behaviour
Animal sexual behaviour takes many different forms, even within the same species. Common mating or reproductively motivated systems include monogamy, polyandry, polygamy, and promiscuity. Other sexual behaviour may be reproductively motivated (e.g. sex apparently due to duress or coercion and situational sexual behaviour) or non-reproductively motivated (e.g. interspecific sexuality, sexual arousal from objects or places, sex with dead animals, homosexual sexual behaviour, bisexual sexual behaviour, and a range of other behaviours).When animal sexual behaviour is reproductively motivated, it is often termed mating or copulation; for most non-human mammals, mating and copulation occur at estrus (the most fertile period in the mammalian female's reproductive cycle), which increases the chances of successful impregnation. Some animal sexual behaviour involves competition, sometimes fighting, between multiple males. Females often select males for mating only if they appear strong and able to protect themselves. The male that wins a fight may also have the chance to mate with a larger number of females and will therefore pass on his genes to their offspring.Historically, it was believed that only humans and a small number of other species performed sexual acts other than for reproduction, and that animals' sexuality was instinctive and a simple ""stimulus-response"" behaviour. A range of species masturbate and may use objects as tools to help them do so.