Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Genetics > Flashcards

Genetics Flashcards

(67 cards)

Start Studying
1
Q

Heredity

A

Passing of traits from parents to offspring

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

Genetics

A

is the study of heredity and variation

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

In a chromosome, genetic information is stored in a molecule of________

A

DNA

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

DNA

A

Has set of chemical instructions for the cell; a gene

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

Gene

A

Portion of DNA that contains information that helps produce trait

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

locus (plural - loci)

A

Each gene occupies a specific location on a chromosome

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

Nucleic acids

A

Are long polymers that hold information to specify the structure of proteins to be made in a cell

These determine the characteristics and functions a cell will have

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

Structure of nucleic acids

A

Made of subunits called nucleotides

Nucleotides are made up of 3 smaller building blocks

  1. Five Carbon sugar ( in a ring )
  2. Phosphate group
  3. Nitrogen Base
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 2 types of Nucleic Acid?

A
  1. DNA

Found in the nucleus and is the main component of genes

The sugar in the nucleotides are called deoxyribose sugar (missing oxygen from 2nd carbon)

Adenine —> Thymine

Guanine —> Cytosine

  1. RNA

Also found in the nucleus, and contains instructions for making proteins.

The sugar in the nucleotides is called ribose sugar.

Guanine —> Cytosine

Adenine —> Uracil`

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

2 types of Nitrogen Bases

A

Purines: Adenine and Guanine (large, double-ringed compounds)

Pyrimidines: Cytosine and Thymine (smaller, single-ringed compounds)

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

Chromatin

A

thread-like structure made up of DNA and proteins in the nucleus of a eukaryotic cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Chromosome

A

structure in the nucleus of a eukaryotic cell that carries genes, formed when chromatin condenses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Chromatid

A

each of the two identical chromosome strands in a replicated chromosome attached by their shared centromere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cells reproduce through controlled growth and division for 3 main functions:

A

Growth

Maintenance to replace dead/dying cells

Repair of tissues/organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the 3 stages of cell cycle

A

Interphase

Mitosis

Cytokinesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Interphase

A

Period between cell divisions

Cell undergoes growth, duplicates hereditary information and prepares for mitosis

Most of cell life is in this stage, misnamed as “resting phase”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What phases is Interphase broken down into? and describe each phase.

A

G1 phase (first gap): cell is growing and preparing for replication

S phase (synthesis): genetic information is replicated

G2 phase (second gap): final preparation for cell division

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

Once cell begins to divide:

A

The nucleus must undergo mitosis

Cytokinesis occurs at the end of the cycle

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

Mitosis

A

stage of the cell cycle during which genetic information is divided equally into 2 nuclei

Occurs in somatic cells

Any cell that is not a reproductive cell

Occurs in most tissues that must replace themselves (eg. skin)

Occurs when a parent cell divides to produce two daughter cells

Daughter cells are genetically identical to parent

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

What are the phases of mitosis?

A

Prophase, Metphase, Anaphase, Telophase

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

Prophase

A

Chromatin condenses into chromosomes, join at the centromere

Nuclear envelope breaks down

Centrioles move to poles, producing microtubules (spindle fibres)

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

Metaphase

A

Spindle fibres begin moving and aligning chromosomes

Chromosomes line up along the equator (metaphase plate)

Chromosomes are condensed and thick

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

Anaphase

A

sister chromatids separate from one another producing 2 single stranded chromosomes

Spindle fibres shorten as they pull the chromosomes to opposite poles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Telophase

A

Chromosomes decondense

Spindle breaks down

Nuclear envelope forms

Cleavage furrow begins in animal cells or cell plate forms in plant cells

Mitosis ends with telophase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Cytokinesis
Division of cytoplasm Cleavage furrow pinches off Formation of two identical daughter cells
26
Somatic Cells
body cells, that have a diploid number of chromosomes (two sets)
27
Cancer
Abnormal cell division; out of control, continuous
28
What are the 2 types of Tumors? And describe each of them
Benign tumours show no signs of spreading Malignant tumors are capable of spreading and invading new tissues (metastasis)
29
How can you treat cancer?
Therapy: radiation, chemotherapy, immunotherapy
30
Sister Chromatids
are when two chromatids are held together by a centromere (they are called sister chromatids because they contain the same type of genes on them) -> "double-stranded" chromosome
31
Homologous Chromosomes
matching pairs of chromosomes, similar in size and shape and have the same genes, arranged in the same order Consist of a chromosome from the male parent and a chromosome from the female parent.
32
Meiosis
Only occurs in eukaryotes that reproduce sexually Only occurs in organisms that are at least diploid Undergoes TWO divisions 1 parent cell produces 4 gamete cells Each gamete cell contains different genetic information
33
What does the creation of gametes rely on?
The creation of gametes relies on meiosis, a specialized process of cell division that produces gametes!
34
How many stages are there in meiosis
The process of meiosis, involves two stages of cell division which in turn reduces the number of chromosomes to half the amount present (becomes haploid).
35
Premeiotic Interphase
DNA replicates Two identical copies of each chromosome are made, attached at centromere Each copy is called a sister chromatid
36
Prophase I
Homologous chromosomes pair together, called a tetrad (each chromosome made of 4 chromatids held together by kinetochore) Each sister chromatid intertwines with a sister chromatid from matching homologous chromosomes, called synapsis Once synapsis occurs, intertwined chromatids from different chromosomes break and reattach to each other CROSSING OVER: Results in recombination of genetic information between non sister chromatids, at random points called chiasmata Centrioles move to opposite poles, and spindle fibres appear
37
Metaphase I
Spindle fibers attach to kinetochore of tetrad Tetrads line up along equatorial plate (middle) Independent assortment occurs Randomly lines up in the middle
38
Anaphase I
Tetrad is pulled apart as each chromosome moves towards the opposite pole Chromosomes are pulled apart at the kinetochore Sister chromatids are still intact
39
Telophase I
Chromosomes reach poles Nuclear membrane reforms Spindle fibres disintegrate
40
Cytokinesis for meiosis
Cytoplasm and organelles divide in half Each daughter cell is haploid (n) One chromosome from each original homologous pair, HOWEVER, sister chromatids still exist
41
Second Meiotic Division: Meiosis II
There is no replication of DNA (interphase II) Chromosomes in daughter cells of meiosis I are in the form of sister chromatids No crossing over occurs (no homologues to synapse)
42
Prophase II
Chromosomes condense Centrioles move to opposite poles Spindle fibres appear
43
Metaphase II
Sets of chromatids move to equator Centromeres divide
44
Anaphase II
Chromatids move to opposite poles
45
Telophase II
Chromosomes unwind, and nuclear envelope forms. Produces 4 haploid cells (sperm or ova) after cytokinesis
46
Cytokinesis II
Product: 4 cells, each with a haploid amount of chromosomes They are all genetically different!
47
2 Methods of Genetic Variability in Meiosis
During Metaphase I of meiosis, homologous chromosome pairs separate randomly. Some gametes may receive all paternal chromosomes or all maternal or a mixture of both. Meiosis is an important source of GENETIC VARIABILITY! Another way in which meiosis contributes to variability is from crossing over during prophase I
48
Gamete Formation (Gametogenesis)
At the end of meiosis, gametes are formed which differentiate into specialized cells Sperm formation (spermatogenesis): Diploid spermatogonia → primary spermatocytes → 4 spermatids Egg formation(oogenesis): Diploid Oogonia → primary oocytes → 1 egg + 3 polar bodies
49
Aneuploidy
Error in meiosis Occurs when chromosomes do not separate properly during meiosis leading to cells having too many or too few chromosomes
50
Nondisjunction
Failure of homologous chromosomes to separate in meiosis I Failure of sister chromatids to separate in meiosis II
51
Monosomy
fertilized cell is missing a chromosome
52
Trisomy
fertilized cell has an extra copy of a chromosome
53
Polyploidy
Every chromosome is duplicated Can be 3n, 4n , etc
54
Nondisjunction Disorders
Results in cells not being able to function properly Responsible for a lot of human genetic disorders Eg. Down's syndrome (trisomy 21): result of nondisjunction of chromosome 21. The offspring receives 3 copies instead of 2. An excess of genetic information causing people with this disorder to have mental and physical differences/challenges
55
List some of the Nondisjunction Disorders
Responsible for: Down Syndrome (trisomy 21) Physical/mental challenges Turner Syndrome (One X chromosome) Females born sterile Klinefelter Syndrome (2 X and 1 Y chromsomes) Males usually sterile; display feminine traits Patau Syndrome (trisomy 13) Developmental problems (brain, kidney, heart)
56
Karyotyping
Karyotyping can be used to diagnose chromosomal abnormalities prenatally Cells for testing can be collected from the amniotic fluid (amniocentesis) or from villi along the lining of the uterus (chorionic villus) Scientists count, compare, arrange chromosomes to see if there are any issues Normally recommended for women over the age of 35
57
Why is a karyotyping important for women over the age of 35?
May be due to oocytes stopping at prophase I until ovulation as part of oogenesis This results in a higher change for nondisjunction in meiosis I from older organelles which age with the individual
58
Inheritance
is the process of genetic transmission of a trait/characteristic from parent to offspring.
59
Allele
A specific form of a gene (eg. purple flower, white flower)
60
homozygous
If an individual has two of the same alleles (eg. both dominant or both recessive)
61
heterozygous
If an individual has two different alleles (eg. one dominant, one recessive) it is considered
62
Genotype
genetic makeup of alleles
63
Phenotype
appearance of a trait
64
What is the purpose of monohybrid crosses?
Mendel recorded his observations of peas using thousands of monohybrid crosses. These crosses are between two organisms (in this case pea plants) with only ONE characteristic that is different. Monohybrid crosses illustrate all of the possible combinations of gametes from a given set of parents. They are used to calculate the probability of inheriting a particular trait.
65
Law of Segregation
Organism inherits 2 copies of genes, one from each parent Organism only donates one copy of each gene
66
Law of Independent Assortment
Law of Independent Assortment states that if genes are on separate chromosomes, they are inherited independently of each other (unlinked)
67
dihybrid cross
A dihybrid cross determines genotypic and phenotypic combinations of offspring for two particular genes that are unlinked. Two genes, each have two alleles, there can be up to four gamete combinations per parent

Biology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions