Lecture 10 Flashcards Preview

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Flashcards in Lecture 10 Deck (24):
1

Homologous chromosomes

The cell has two sets of chromosome; one is from the mother and the other from the father

2

Karyotype

the number and visual appearance of the chromosomes in the cell nuclei of an organism or species

3

Autosomes

any chromosome that is not a sex chromosome

4

Sex chromosomes

a chromosome that determines the sex of an organism

5

Diploid (2n)

Two gametes form a diploid zygote with two copies of autosomal chromosomes

6

Haploid (n)

is the number of chromosomes in a gamete

7

Meiosis

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores

8

Mitosis

a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

9

Gametes

a mature haploid unites with another of the opposite sex in sexual reproduction to form a zygote

10

Asexual Reproduction

is a type of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only; it does not involve the fusion of gametes and almost never changes the number of chromosomes

11

Asexual Reproduction Advantages

- No time finding a
mate (less energy)
- All of your alleles are
passed on (more
genetic representation
in next generation)
- Fast reproduction

12

Asexual Reproduction Disadvantages

All offspring identical

13

Sexual Reproduction

the production of new living organisms by combining genetic information from two individuals of different types (sexes

14

How does the cell reduce its genetic information for
reproduction?

Meiosis!!

15

Meiosis Overview

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
5. Repeat

16

Prophase I

homologous pairs form tetrads and exchange sections of DNA in a process called crossing-over.

17

Prophase II

The duplicated chromosomes and spindle fibers reappear in each new cell.

18

Metaphase I

homologous chromosomes line up in the center of the cell. Each chromosome pair attaches to one spindle fiber.

19

Metaphase II

The duplicated chromosomes move to the center of the cell. Each centromere attaches to two spindle fibers instead of one.

20

Independent Assortment

chromosomes are inherited freely from one another
traits on different chromosomes have an
equal chance of occurring together

21

Anaphase I

Chromatids do not seperate. The two pairs of chromatids move to opposite ends of the cell. Each duplicated chromosome still has two chromatids.

22

Anaphase II

The centromere divides. The chromatids seperate and move to opposite ends of the cell. Each chromatid is now an individual chromosome.

23

Telophase I

The cytoplasm divides and two new cells form. Each new cell has one duplicated chromosome from each similar pair.

24

Telophase II

The spindle fibers disappear, and a nuclear membrane forms around each set of chromosomes, forming 4 haploids