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Flashcards in genetics final Deck (275)
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1

what is genetics

study of inheritance of observable traits from one generation to next, and effect on population and species

2

what is molecular biology?

molecular processes involved in transfer of genetic information from genotype to phenotype of organism

3

what is a phenotype?
- what determines it
example

physical and biochemical traits
- genotype determines it

ex: flower colour, ear shape, genetic disease

4

what is a genotype?

organisms genetic makeup

genetic info contained in genes

5

structure of DNA molecule

what does it carry

- long strands of DNA
- double helix


carries genetic info which determines phenotype

6

what joins strands of DNA molecule

hydrogen bonds between bases

7

bases of DNA molecule

bases of RNA molecule

4 bases= genetic alphabet

DNA: TAGC
RNA: UAGC

8

4 parts of structure of eukaryotic chromosome

- telomere (end)
- centromere (constricted region)
- long arm
- short arm

9

what is chromatin

DNA + protein

10

dense region in prokaryote DNA

nucleoid

- not membrane bound

11

human karyotype

23 pairs homologous chromosomes

- display pairs of cells arranged by size and shape

12

what is a homologous chromosome

pair of chromosomes with same morphology (size/shape)
- same length, centromere position, staining pattern

- 1 inherited from father other from mother

13

what form is cell in when not dividing, DNA is replicated in preparation for division

each chromosome is in form of long chromatin fibre

14

what is a sister chromatid?

joined copies of the original chromosome (joined at centromere)

- each duplicated chromosome has 2 sister chromatid

15

where do sister chromatids attach?

cohesin

- protein complexes
- called sister chromatid cohesin

16

what is a centromere

region containing specific DNA sequences

17

diploid

number of chromosomes

- multiple of 2

(eukaryotes)

18

human sex chromosomes characteristics (2)

1) different morphology
2) referred to as homologous chromosomes

X & Y

19

DNA complexed with proteins called..

histones

20

avg human chromosome has how much DNA? (length)

5cm

21

what is a genome

the genetic information, the cells DNA

22

process organization of DNA in chromatin

- double helix DNA wraps twice around histones (ball proteins)
- packaged into nucleosomes (beads on string)
- bundled together in 30nm fibre= solenoid
- solenoid makes looped domains of chromatin= 300nm
- looped domains make metaphase chromosome during cell division

23

4 part hierarchical structure of chromosome

- 10 nm fiber (beads on string)
- 30nm fiber (solenoid)
- chromosome looped domains
- metaphase chromosome

24

2 parts of cell cycle

interphase
m phase

25

3 parts to interphase

G1 phase- primary growth
S phase- synthesis, DNA is replicated
G2 phase- final preparation for division

26

what phase is DNA replicated

S phase of interphase

27

what is m phase?

mitotic phase (process of mitosis)

- division of genetic material into cells

28

5 parts of m phase

1) prophase
2) metaphase
3) anaphase
4) telophase
5) cytokinesis

29

what happens during prophase?

- chromatin fibres condensed into chromosomes
- nucleoli disappear
- duplicated chromosomes appear as 2 sister chromotids joined at centromeres
- mitotic spindle begins to form, composed of centrosomes, microtubules extend from them
- centrosomes move away from each other, propelled by microtubule

30

what happens during metaphase?

- centrosomes at opposite poles
- chromosomes convene at metaphase plate
(centromeres lie at equator of cell)