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Genes - Unit3and4Biology
Genes - Unit3and4Biology

... phenotype of the heterozygous individual displays the dominant allele (e.g. the heterozygous Qq will exhibit a widows peak ).  Incomplete dominance – occurs when there is a blending of the two alleles in the heterozygous individual (e.g. an allele for red flowers and an allele for white flowers res ...
Cell Growth and Reproduction
Cell Growth and Reproduction

... After the cell has prepared for reproduction during interphase, the nuclear envelope falls apart as the chromatids coil up to form chromosomes, which are joined at the centromere (Figure 4-30) ...
Slide 1
Slide 1

... Crosses between F1 offspring produced 3:1 phenotypic ratio in F2 offspring The white-eyed trait appeared only in males Morgan concluded that a fly’s eye color was linked to its sex ...
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... - Tall male with heavy acne - Some tendency to mental ...
Chapter 10 PowerPoint
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... instead of one and both become fertilized.  Identical: When a female ovulates one egg and after fertilization that one egg splits giving both ...
04BIO201 Exam 1 key
04BIO201 Exam 1 key

... b. Label the sister chromatids. c. How many individual molecules of DNA are present in the cell at prophase of mitosis? 8 homologous chromosomes ...
What have these animals got in common? - pams
What have these animals got in common? - pams

... Different genes control the development of different characteristics by giving instructions to the cell. These instructions are carried inside the nucleus by chromosomes. These instructions are made of a chemical called DNA. ...
Genetic variation
Genetic variation

...  Aneuploidy – the chromosome number is not an exact multiple of the haploid number e.g. trisomy  Polyploidy – if a diploid gamete is fertilized by a haploid gamete, the resulting zygote will be triploid. The fusion of 2 diploid gametes leads to a tetraploid zygote. Many cultivated plants are polyp ...
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... number from diploid to haploid • Meiosis I – Prophase I key events • The nuclear membrane dissolves. • Chromatin tightly coils up. • Homologous chromosomes, each composed of two sister chromatids, come together in pairs in a process called synapsis. • During synapsis, chromatids of homologous chromo ...
File - Ms. Daley Science
File - Ms. Daley Science

... UNIT 5: CELLULAR AND ORGANISMAL REPRODUCTION: (Chapters 8, 27, and 31) 123. How do bacteria reproduce? 124. What is mitosis? What is its major characteristic? 125. What occurs during S, G1 and G2 stages of the cell cycle? 126. List the phase of the cell cycle and briefly tell what happens at each st ...
No Slide Title
No Slide Title

... Copyright 1999 by John Wiley and Sons, New York, NY. All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, wi ...
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The Cell Cycle EnBio

... OpenStax-CNX module: m55567 ...
Glossary of Terms - Liverpool Womens NHS Foundation Trust
Glossary of Terms - Liverpool Womens NHS Foundation Trust

... The precise physical site or location of a specific gene on a chromosome. p denotes the short arm of the chromosome q denotes the long arm of the chromosome MITOCHONDRIA Refers to the small bodies that are responsible for energy production. Mitochondria also carry their own genes and DNA. MITOCHONDR ...
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Prentice Hall Biology

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Concept 3 - Ms DeBeaudrap Science

...  Refer to this as the ________________________________ – a language the cell understands  These chemicals are _____________________________________ ___________ on Earth  ________________ are packages within the cell which contain the ...
cell cycle - Effingham County Schools
cell cycle - Effingham County Schools

... microtubules that controls chromosome movement during mitosis • In animal cells, assembly of spindle microtubules begins in the centrosome, the microtubule organizing center • The centrosome replicates during interphase, forming two centrosomes that migrate to opposite ends of the cell during propha ...
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... chromosomes in each of its sperm cells, how many chromosomes are in each of its body cells? Hint, think meiosis. ...
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... first mitotic division, the cells produced by the zygote will have— a) 52 chromosomes. b) 39 chromosomes. c) 26 chromosomes. d) 13 chromosomes ...
Name: Date: Period: Activity 3.3.1: How is DNA Passed Through the
Name: Date: Period: Activity 3.3.1: How is DNA Passed Through the

... represented as lowercase letters. Therefore, the gene for brown and blue eyes can be represented with the letter B (or b). The capital letter B often represents the dominant gene for brown eyes and the lowercase b represents the recessive gene for blue eyes. Therefore, someone with the genotypes BB ...
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... kinetochores move to opposite poles  pulled at centromeres  pulled by motor proteins “walking”along microtubules ...
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... • The DNA structure is maintained via association with different protein – formation of the DNA-protein complex – chromatin. •Before the cell can divide all DNA must be copied and then separated to daughter cells. •After copying each duplicated chromosome consists of two sister chromatids –identica ...
45 Minute Content Lesson Plan
45 Minute Content Lesson Plan

... Before answering each of the questions the students copied into their notebooks, I will quickly review ratios with the students. Once I feel as though they understand ratios, I will go over the answers to each of the questions. As I am answering each question, I will have pictures of the stages of m ...
lesson plan - Achievement First
lesson plan - Achievement First

... 3. Identify the whether the process relates to asexual or sexual reproduction: ________ A diploid prokaryote divides to produce two new diploid cells ________ Dead skin cells are replaced by new identical cells ________ Sperm and egg cells fuse ________ An amoeba, a eukaryotic single-celled organism ...
Chapter 5 DNA and Chromosomes
Chapter 5 DNA and Chromosomes

... Genes – the information-containing elements that determine the characteristics of a species as a whole and of the individuals within it. A gene is usually defined as a segment of DNA that contains the instructions for making a particular protein (or, in some cases, a set of closely related proteins) ...
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... many proteins in the hemoglobin molecule. b) Sickle cell disease. A single base change in DNA codes via RNA for a different amino acid, valine. But this critical amino acid is important in proper folding of the hemoglobin molecule, which becomes defective, producing sickled red blood cells. ...
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Meiosis



Meiosis /maɪˈoʊsɨs/ is a specialized type of cell division which reduces the chromosome number by half. This process occurs in all sexually reproducing single-celled and multi-celled eukaryotes, including animals, plants, and fungi. Errors in meiosis resulting in aneuploidy are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells each with half the number of chromosomes as the original parent cell. The two meiotic divisions are known as meiosis I and meiosis II. Before meiosis begins, during S phase of the cell cycle, the DNA of each chromosome is replicated so that it consists of two identical sister chromatids. In meiosis I, homologous chromosomes pair with each other and can exchange genetic material in a process called chromosomal crossover. The homologous chromosomes are then segregated into two new daughter cells, each containing half the number of chromosomes as the parent cell. At the end of meiosis I, sister chromatids remain attached and may differ from one another if crossing-over occurred. In meiosis II, the two cells produced during meiosis I divide again. Sister chromatids segregate from one another to produce four total daughter cells. These cells can mature into various types of gametes such as ova, sperm, spores, or pollen.Because the number of chromosomes is halved during meiosis, gametes can fuse (i.e. fertilization) to form a zygote with a complete chromosome count containing a combination of paternal and maternal chromosomes. Thus, meiosis and fertilization facilitate sexual reproduction with successive generations maintaining the same number of chromosomes. For example, a typical diploid human cell contains 23 pairs of chromosomes (46 total, half of maternal origin and half of paternal origin). Meiosis produces haploid gametes with one set of 23 chromosomes. When two gametes (an egg and a sperm) fuse, the resulting zygote is once again diploid, with the mother and father each contributing 23 chromosomes. This same pattern, but not the same number of chromosomes, occurs in all organisms that utilize meiosis. Thus, if a species has 30 chromosomes in its somatic cells, it will produce gametes with 15 chromosomes.
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