Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SBI3U > Chapter 4 > Flashcards

Chapter 4 Flashcards

1
Q

Define Heredity

A

the passing of traits from parents to offsprings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define Genetics

A

the branch of biology dealing with heredity and the variation of inherited characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define Genes

A

segment of DNA that codes for a particular trait: found at specific locations on a chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define Locus

A

the location of a gene on a chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define DNA (Deoxyribonucleic acid)

A

a macromolecule that carries genetic information in cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define allele and two types of alleles

A

Most genes have two or more variations called alleles
- Dominant Allele: An allele that if present, it’s trait is expressed
(ie. Ww or WW)
- Recessive Allele: An allele that is masked by the dominant allele if present recessive trait is only expressed if only recessive alleles are present (ie. ww)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Difference between phenotype and genotype

A

Phenotype: physical trait and individual shows (ie. widow’s peak)
Genotype: allele combination an individual has (ie. WW, Ww, ww)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define Mitosis

A

a process of nuclear division in eukaryotic cells that occurs when a parent cell divides to produce two identical daughter cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where does mitosis occur?

A

Somatic cells (cells of the body)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the phases of cell cycle?

A

Interphase - G1 (growth), S (DNA synthesis), G2 (growth)
Mitosis
Cytokinesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Prophase - Mitosis

A
  • pairs of sister chromatids
  • Chromatin condenses to form chromosomes
  • Nuclear membrane breaks down
  • Duplicated centrioles migrate to opposite poles
  • Spindle fibers begin to form
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Metaphase - Mitosis

A
  • Spindle fibers attach to chromosome
  • Centromere align along equatorial plate
  • Sister chromatids face opposite poles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Anaphase - Mitosis

A
  • Centromere splits
  • Sister chromatids are pulled to opposite poles by spindle fibers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Telophase - Mitosis

A
  • Nuclear membrane forms around each set of chromatids
  • Spindle fibers disappear
  • Chromatids decondense to chromatin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Cytokinesis

A
  • division of cytoplasm
  • occurs at the end of mitosis and beginning of interphase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Purpose of Mitosis

A
  1. growth
  2. repair
  3. maintenance
  4. asexual reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Types of asexual reproduction

A

binary fission - asexual where a parent cell results in two identical cells

fragmentation - asexual reproduction where a parent organism breaks into fragments each capable of growing independently into a new organism

budding - asexual reproduction where a new individual develops from some generative anatomical point of the parent organism

vegetation propagation - asexual plant reproduction that occurs in its leaves, roots, and stem

spore formation - plants produce hundreds of spores and the spore sac bursts, spores are dispersed into the air, where they germinate and create a new plant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Biotechnology

A

use and or modification of an organism for applications in engineering, industry, and medicine
- human benefits
- cloning plants for use in agriculture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cloning

A

process of producing one individual that is genetically identical to another, using a single cell or tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Plant cloning and 5 types

A

used to produce strains of plants with identical characteristics and used commercially
- ie. leaf cutting, grafting, stem cuttings, budding, runners

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Genetically Modified Organisms (GMO)

A

genetic material of an organism has been altered using genetic engineering techniques

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

pros and cons of cloning animals and plants

A

Plant Cloning
pros
- To produce identical plants quickly and economically
- Effective way of producing new invidiuals from rare and endangered plants, helping to preserve the species
cons
- No genetic variation

Animal Cloning
pros
- Produces healthier animals, which minimizes the use of antibiotics, growth hormones and other chemicals
cons
- Defects in vital organs, such as the liver, brain, and heart
- Seen as unethical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Sexual Reproduction

A
  • each parent contributes a copy of half of its genetic information
  • results in being genetically different from parents
  • produces genetic variety
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Asexual reproduction

A
  • produces offspring genetically identical to a single parent
25
Q

What are the two key processes of sexual reproduction?

A
  1. Formation of haploid sex cell or gametes
  2. Fertilization, which occurs when two sex cells join to produce a zygote (fertilized egg cell)
26
Q

What reproductive organs produce what sex cells?

A

Tests produce sperm in males. Ovaries produce ova (egg cells) in females.

27
Q

Define meiosis

A

process where haploid gametes are formed
- chromosomes number of the daughter cells is half of the parent cell
- human cell with 46 chromosomes undergoes meoisis to produce gamete with 23 chromsomes (haploid)

28
Q

One from Mom one from Dad

A
  • offspring receives complete set of genetic instructions from each parent
  • one version from from father and one from mother
29
Q

Homologous chromosomes

A
  • 23 chromosomes from your father is matched to 23 chromsomes from mother
  • paired chromsomes are called homologous chromsomes
  • similar in size and shape and carry the genetic info for the same gene
30
Q

Fertilization

A
  • haploid sperm cell (23) unites with a haploid egg cell (23) to form diploid zygote (46)
  • the zygote grows and divides that produces a mature multicellular individual
31
Q

2 phases of meiosis

A
  • two divisions that produce four haploid cells
  • Meiosis I (reduction division) where diploid chromosome number is reduce by half to the haploid chromosome number
  • Meiosis II, number of chromsomes i unchanged, total number of cells increase to four
32
Q

Meiosis I - Prophase I

A
  • DNA replication happens during interphase prior to the start of meiosis
  • prophase I, chromosome start to shorten and thicken
  • each chromosome consists of two sister chromatids joined at the centromere
  • nuclear membrane begins to dissolve, centrioles separate, and move to opposite poles of the cell and spindle fibres form
  • chromsomes come together in homologous pairs
    - each chromosme of the pair is composed of a pair of sister chromatids
    - whole structure called a tetrad beccause each pair of chromosme has four chromatids
  • each sister chromatid intertwines with a sister chromatid with its matching homologous chromsome, a process called synapsis
    - crossing over (mixing of genetic info)
33
Q

Meiosis I - Metaphase I

A
  • tetrads (made up of pairs of homologoud chromsomes) migrate twoards the centre of the cell and align their centromeres across the middle of the cell
34
Q

Meiosis I - Anaphase I

A
  • homologous chromosomes move to opposite poles of the cell
  • reduction division occurs
  • only one chromosome from each homologous pair will be found in each new daughter cell
  • each chromosome in the new cell consists of two sister chromatids
35
Q

Meiosis I - Telophase I

A
  • nuclear membrane begin to form around the chromsomes at each end of the cell and the cell begins to divide
  • chromosomes in the two nuclei are not identical
  • cells are now haploid
36
Q

Meiosis II

A
  • begins immediately after telophase I and no duplication of between meiosis I and II
  • each haploid daughter cell contains one set of chromosomes
  • chromsomes still consist of two sister chromatids that are not identical
37
Q

Meiosis II - Prophase II

A
  • nuclear membrane dissolves and spindle fibres begin to form
38
Q

Meiosis II - Metaphase II

A
  • Each with two sister chromatids across the middle of the cell
  • sister chromatids remain attached by centromeres
39
Q

Meiosis II - Anaphase II

A
  • sister chromatids separate and move to opposite poles of the cell
  • nuclear membrane begins to form around the chromatids now called chromosomes
40
Q

Meiosis II - Telophase II

A
  • second nuclear division is completed and the second division of cytoplasm follows
  • four genetically different haploid daughter cells (Gametes) have been produced
41
Q

Random assortment

A
  • a daughter cell can receive either chromosome of each homologous pair called random assortment
  • for any diploid (2n) organism the number of combinations is 2^n
    - ie. 23 pairs of chromosomes, 2^23=8388608
    - does not include added variation from crossing over
42
Q

Define gametogenesis

A
  • formation of sex cells (haploid) in meiosis
43
Q

Define spermatogensis

A

production of sperm cells
- cytoplasm is divided equally during each cell divsion results in four equal sized sperm cells
- small in size and streamlined for maximum motility to be able to swim to an egg cell and fertilize it

44
Q

Define oogenesis

A

production of egg cells (ova)
- cytoplasm of the female gametes does not divide equally during each of the two cell division of meiosis
- one daughter cell receives most of the cytoplasm
- other cells, called polar bodies die, and final product is a single ovum (egg cell)
- does not have to be mobile so it can contain a large supply of nutrient in their cytoplasm to fuel future cell division

45
Q

karyotype

A
  • chromosomes of an individual that have been sorted and arranged according to size and type
  • can be used to evaluate chromosomes to diagnose genetic disorder
46
Q

X and Y chromosomes

A
  • large chromosome is called an X chromosome and smaller chromosome is called a Y chromosome
  • XX is female and XY is male
  • X chromosomes always come from the mother and father either provides an X or Y chromosome
47
Q

Define autosomes

A
  • chromosomes that are not sex chromosomes
48
Q

Difference between euploidy and aneuploidy

A

euploidy: a cell or organism have an exact multiple of the haploid number
aneuploidy: a cell or organism having an incorrect number of chromosomes
- results in nondisjunction during meiosis

49
Q

difference between monosomy and polysomy

A

monosomy = chromosome missing
polysomy = additional chromosomes (ie. trisomy where there are three homologous chromosome in place of a homologous pair)

50
Q

Nondisjunction in meiosis I and II

A

meiosis I
- during Anaphase I, no normal gametes will be created
- homologous chromosomes fail to separate

meiosis II
- during anaphase II, half of the gametes will have the correct chromosome number
- sister chromatids fail to separate

51
Q

Down Syndrome

A

trisomy 21 - extra homologous chromosome at chromosome 21

52
Q

Turner syndrome

A

one X and no Y sex chromosome (X)

53
Q

Klinefelter syndrome

A

two X and one Y sex chromosome (XXY)

54
Q

Patau syndrome

A

Trisomy 13

55
Q

Edwards syndrome

A

trisomy 18

56
Q

Prenatal testing

A
  • testing for a genetic disorder prior to birth
  • recommended for pregnant women over the age of 35 due to increased risk
57
Q

three Errors in crossing over

A

insertion/deletion - unequal crossing over between homologous pairs (one missing genes and one extra genes)
inversion - segment of chromosomes rotates before reattaching (genes in incorrect order)
translocation: segment of two non-homologous chromosome crosses over (ie. chromsome 5 crossing over with chromosome 11 instead of two chromosome 5s)

58
Q

Ways to fix problems with Fertilization

A

Assisted Reproductive Technologies (ARTS)
- in vitro fertilization - egg cells are combined sperm cells outside the uterus, fertilized egg is then implanted in the uterus and begins pregnancy
- artificial insemination - placing sperm into reproductive tract of a female

59
Q

non human applications of Assisted Reproductive Technologies (ARTS)

A

Artificial insemination used in breeding livestock, wild animals, pets
- to enhance genetic diversity and reduce costs by using frozen sperm
- valuable tool to save endangered species

problems
- creating gene banks and related technologies can be expensive
- trying to preserve endangered species in frozen banks may undermine efforts to preserve the species in the wild

SBI3U (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions