Lecture Notes exam 2 Flashcards Preview

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1

Sexual Reproduction

offspring arise from two parents and a mixture of genes are inherited from both, offsprings will have better chance of survival of effects of mutations

2

Asexual Reproduction

produces genetically identical copies of a single parent (clones)

3

Mitosis

somatic cells, purpose of growth, repair and replace, diploid to diploid

4

Meiosis

division of specialized cells that form reproductive cells known as gametes. A diploid cell into 4 haploid gametes. Nuclear division, halves chromosome number

5

2 Haploid Gametes fuse to produce

zygote

6

Zygotes are

diploid 2n

7

Gametes do not__, they ___

divide, produced by germ cells by meiosis

8

How many chromosomes in human somatic cell and how many pairs

46;23

9

Mitosis ___ chromosome number. Meiosis ___ chromosome number

maintain; reduce.

10

Haploid

single set of chromosome (n)

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Diploid

double set of Chromosome (2n)

12

Genes

regions in an oragnism's DNA that encode information about heritable traits. Pairs on homologous chromosomes.

13

Alleles

Different versions of the same gene.

14

DNA is replicated

Once

15

Meiosis 1

Diploid germ cell replicated its chromosome and form tetrad (pairs of duplicated homologous chromosomes); each duplicated homologous chromosome is separated from its partner

16

Meiosis II

two haploid cells cells divide, sister chromatids are separated (like in mitosis)

17

Stages of Meiosis I

Prophase: homologous chromosomes condense, pair up, and swap segments. Aka crossover stage
Metaphase: Chromosomes line up
Anaphase: Chromosomes separate
Telophase: A new nuclear envelope cause so two haploid nuclei form.

18

Stages of Meiosis II

Prophase II: the chromosomes condenses with no dna replication
Metaphase II: chromosomes align
Anaphase II: Sister chromatids separate
Telophase II: 4 haploid cells

19

Crossover

happens in proffer I, helps with genetic variability. mixture of both parents.

20

random assortment produces

2^23 possible combinations of homologous chromosome

21

Sporophytes

Diploid bodies with specialized structures that form spores (haploid cells) that give rise to gametophytes through mitosis

22

Gametophytes

A multi-celled haploid body inside which on ore more gametes form

23

fertilization

fusion of two haploid gametes (sperm and egg) resulting in a diploid zygote

24

Genes occur in pairs of

homologous chromosomes

25

Gregor Mendel

Breeding garden pea plants

26

Characters

heritable features that vary among individuals

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Traits

variants for a character

28

Genes

Discrete heritable units of information for traits

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Alleles

Alternative forms of a gene

30

Each gene has a specific ___on a chromosome

locus