Module 5: Heredity Flashcards

Question

What do oestrogen and progesterone do?

Answer 1

Estrogen and progesterone levels regulate ovarian and menstrual cycles and create ideal conditions for ovulation, implantation and maintaining pregnancy.

Answer 2

1.Pollem (sperm) removed from the stamen of one plant 2.Pollen applied to the stigma of another plant 3. Pollen fertilizes the ovum. -Both agricultural and domestic plant breeders use this process to breed plants with specific characteristics such as colour, size and yield. (VANILLA- one species of bee)

Answer 3

1.Detection of female cows in oestrus 2.Collection of semen 3. Insemination usually performed using an insemination gun which shoots semen into the cervix of the desired animals.

Answer 4

-The intentional mating of individuals with desirable traits in the hope that offspring will express those same traits in their phenotype -Its prevalent in sheep pigs, cows, chickens, fish, prawns etc -Sheep have been selected for the quality and quantity of the wool they grow and beef cattle for their muscle mass 1.Determine the desired breed 2.Interbreed parents that show the desired trait 3.Select the offspring with the best form of the trait and breed these offspring 4.Continue this process until the population reliably produces the desired trait -EXAMPLE: Jersey or Angus cows

Answer 5

-Process of a gene being removed from one species and inserted into the genome of another species -The protein produced by the gene is then expressed in tge genotype of the second species

Answer 6

BT -Bt is a bacteria species producing a toxic that is toxic to select insect pests -Gene is isolated from BT and inserted into cotton and rice to produce a transgenic species called BT cotton or rice. -Natural insecticide that kills insects- higher yield GM Atlantic salmon -Growth hormone from the chinook salmon and a gene from the eel-like ocean pout which switches on the Chinook’s growth hormone -Allows them to grow all year round.

Answer 7

Cloning is the process by which genetically identical copies of an organism are made without using the process of sexual reproduction. The most common method (and the oldest) is grafting. The plant and fruit produced is a clone of the original plant. This is seen commonly in fruit crops.

Answer 8

Without knowing Mendel, Chargaff and Watson and Crick we wouldn't be able to manipulate at all.

Answer 9

-Cell division resulting in two identical daughter cells, with the same number and kind of chromosomes as the parent cell. -Mitosis plays an important role in growth, repair, asexual reproduction and genetic stability

Answer 10

Cell prepares itself for division -DNA replication occurs to produce two copies of each chromosome. -Period of growth and normal activity

Answer 11

Duplicated chromosomes condense -Chromosomes become visible and the centrioles separate and move to opposite poles of the cell. -Microtubules that are apart of mitotic spindles that lengthen and shorten to pull chromatids apart.

Answer 12

Prometaphase: Nuclear envelope breaks down -Pairs of condensed chromosomes (called sister chromatids) line up along the equator of the cell -Each pair of chromosomes are attached to different spindle fibers to move in the opposite direction.

Answer 13

Chromatids separate and move towards opposite poles of the cell by the mitotic spindle There is now only one copy of each chromosome at either end of the cell.

Answer 14

Two new nuclear envelopes form around the separated sister chromatids Chromosomes spread out again -Nucleolus reappears and spindle fibers disappear

Answer 15

Two daughter cells are separated by. The tightening of a ring of proteins around the middle of the dividing parent cell- the two nuclei are squeezed apart -Cytokinesis occurs simultaneously to anaphase and telophase- the pinching of the cellular membrane begins to happen as chromosomes are separated and new nuclei are formed.

Answer 16

-Cell division resulting in four genetically unique daughter cells (gametes) each with half the number of chromosomes (haploid) of the parent cell (diploid) -Creates sex cells- half as many chromosomes as mitosis- iInvolves two successive divisions of the nucleus

Answer 17

Chromosomes that share the same structural features, carrying the same kind of genetic information, but may have different alleles.

Answer 18

Process where chromosomes move randomly to separate poles during meiosis (Metaphase 1)

Answer 19

-As with mitosis, DNA replication occurs to produce two copies of each chromosome.

Answer 20

Chromosomes condense and the nuclear envelope breaks down (prometaphase) -Homologous chromosomes pair up, aligning next to each other along their full length -Crossing over occurs between homologus chromosomes- segments of DNA at the same locus to create new gene combinations.

Answer 21

- Homologous pairs (not individual chromosomes) line up along the equator of the separating cell.

Answer 22

- Homologous pairs are separate, pulled to opposite ends of the cell by the mitotic spindle -Sister chromatids remain attached

Answer 23

-Chromosomes arrive at opposite ends of the cell -Two diploid daughter cells are formed by cytokinesis.

Answer 24

-Chromosomes condense and the nuclear envelope breaks down

Answer 25

- Chromosomes line up along the equator of the dividing cells.

Answer 26

- Sister chromatids are separated by the spindle microtubules and pulled towards opposite poles of the cell.

Answer 27

-Cytokinesis splits the dividing cell into two new cells -Nuclear membranes form around each set of chromosomes -Four haploid daughter cells are formed each containing half the number of chromosomes of the parent cell.

Answer 28

Four fully seperate cells

Answer 29

A monomer of DNA that consists of phosphate group joined to a deoxyribose sugar which is attached to a nitrogenous base of adenine, thymine, cytosine or guanine.

Answer 30

Also called a nitrogenous base. Bases are the nitrogen-containing molecular units that make up a nucleic acid.

Answer 31

A pair of parallel spirals intertwined around a common axis.

Answer 32

There are two-sugar phosphate backbones on the outside, which are held together by hydrogen bonds between pairs of nitrogenous bases on the inside.

Answer 33

An attractive force between the hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule.

Answer 34

DNA replication is the process by which the double stranded DNA molecule is ‘unzipped’ by enzymes and free nucleotides bind t each of the exposed backbones to create two identical DNA molecules. Cells copy genetic information before cell division so that each new cell has a complete set of DNA.

Answer 35

Unwind (Topoisomerase unwinds the coiled strands of DNA), unzip (DNA helicase unzips the strands of DNA< breaking the hydrogen bonds creating two template strands for replication, HO (Single strand binding proteins (SSB) keep the strands seperated, BP (DNA polymerase III bonds free nucleotides with nucleotides on each parents strand using base pairing rules, proofread (DNA poly1 proofreads new strands and backtracks over errors), JN (DNA ligase bonds backbone back together)

Answer 36

-Complimentary base pairing results in double-stranded DNA -Both DNA strands run anti-parallel to each other (oriented in different directions) -One strand is 5’-3’ while the other is 3’-5’. -DNA ONLY REPLICATES IN THE 5’ TO 3’ DIRECTION: replication will be continuous for one strand (the leading strand) and discontinuous for the other strand (the lagging strand)

Answer 37

: Directional movement of replication -Nucleotides area added in the SAME direction as the replication fork- creating a continuous leading strand. -Nucleotides added in the opposite direction as the replication fork creates okazaki fragments on the lagging strand. -Polymerase III only works in 5’ to 3’ direction on BOTH parent strands- THUS creating continuous replication on the leading strand.

Answer 38

Short sequences of DNA nucleotides that are synthesized discontinuously and later linked together by DNA ligase to create the lagging strand in DNA replication.

Answer 39

-The insertion of an incorrect base is common during DNA replication -A repair enzyme detects these and snips it out, replacing it with the correct base -This is called a DNA mismatch repair- function of DNA polymerase I.

Answer 40

-If errors aren’t picked up quickly and remain undetected they can replicate and cause a permanent mutation. -If the mutation occurs during meiosis- it can be passed on to the offspring as well (importance of replication accuracy)

Answer 41

-Increases the number of cells in an organism, allowing for development of a multicellular body -Mitosis allows for cell renewal and replacement- ensuring an effective function -Mitosis allows human to develop to maturity when we can pass our genetic information onto offspring through sexual reproduction -Some organisms reproduce asexually- facilitated by mitosis -In this case, mitosis creates the next generation of organisms (species continuity)

Answer 42

Combination of gametes during sexual reproduction creates new organisms- inherited traits from both parents -Meiosis purposefully introduced variation -Processes of crossing over, independent assortment, and random segregation allow for combos of different alles- increasing genetic variation in offspring and wider species population. -The genetic diversity caused by meiosis is important for the continuity of species as mutation and variation are essential factors for survival and evolution.

Answer 43

The replication of genetic material ensures that information important for life is transferred down through generations -If DNA wasn’t replicated before mitosis and meiosis (during interphase), cell division would have half the amount of DNA, and resulting cells would die- inadequate amounts of genetic information -DNA replication is a high fidelity process: ensuring that daughter DNA strands carry the same gene- encoding all the essential proteins for life

Answer 44

The prokaryote has a circular, double-stranded piece of DNA, not surrounded by a nuclear membrane -Small circular, independent, double-stranded DNA molecules -DNA is not bound by proteins (such as histones like in eukaryotic DNA) -Proteins have smaller, more compact genomes, little repetitive DNA -Has small and extra chromosomal segments of DNA called plasmids

Answer 45

Linear, associated with histones and is found in the nucleus -Chromosomes are paired

Answer 46

A gene that is switched ON is transcribed, translated, turned into a polypeptide and thus a functional protein (special proteins called transcription factors or DNA binding factors control which genes are transcribed by binding to a specific DNA sequence)

Answer 47

-Flower color is determined by soil ph. -The pH effects the availability of other ions in the soil and these ions are responsible for a color change. -pH less than 5= blue flowers in acidic soil -pH more than 7= neutral and alkaline soul=pink flowers.

Answer 48

Linear molecules, made up of multiple peptides Are the functional unit, made up of one or more polypeptides. -Proteins have a very defined structure determined by the sequence and folding of amino acid chains. This ultimately determines the function of the protein.

Answer 49

The process by which a complementary copy (mRNA) of a gene (DNA) is made in the nucleus.

Answer 50

The process of turning information encoded as mRNA into a polypeptide chain (to then become proteins) -It uses mRNA codons (3 sets of bases) as the template for coding the sequence of amino acids to form a polypeptide chain -RNA anticodons carry the appropriate amino acids into place -The genetic sequence of the mRNA is read by ribosomes -The code is translated in groups of three nucleotides called a codon

Answer 51

-RNA polymerase binds to the promoter sequence upstream from a gene -As RNA polymerase moves along the DNA strand, a mall region of DNA is unwound -RNA polymerase ‘reads’ the DNA template strand, matching complementary free-floating nucleotides to create an mRNA chain containing the same coding information. -A mRNA molecule is sequentially synthesized by RNA polymerase as it continues to move along the DNA strand Terminator sequences end the transcription of DNA, and the newly formed RNA molecule is released.

Answer 52

-mRNA docks to a ribosome -The ribosome matches a complementary tRNA molecule to the mRNA by matching codon-anti-codon sequences -As subsequent tRNA molecules dock, a polypeptide forms between the adjacent amino acid molecules they carry -As the mRNA molecule continues to be read, the polypeptide chain is elongated by continued addition of amino acids -When a stop sequence is reached, the ribosome releases mRNA and polypeptide molecule -The polypeptide folds and undergoes post-translational modifications, resulting in a mature protein, ready for use within the cell.

Answer 53

-DNA doesn’t leave the nucleus, as a result, a message must be sent from the nucleus to the ribosomes where protein synthesis occurs. -mRNA is essential to carry the genetic code stored in DNA from the nucleus to the ribosomes in cytoplasm

Answer 54

tRNA carries the specific amino acid to be joined into the polypeptide chain -As a result of the contemporary nature of the mRNA and tRNA codon-anti-codon complex, the specific sequence of amino acids required for protein synthesis occurs.

Answer 55

-Incomplete dominance occurs when one allele for a specific trait is not completely expressed over its paired allele -This results in a third phenotype in which there is a blending of the alleles in their own phenotype

Answer 56

Co-dominance occurs when alleles of a gene pair in a heterozygote are both fully expressed in the phenotype-neither are dominant or recessive

Answer 57

Affected daughters from affected fathers

Answer 58

Affected sons from affected mothers

Answer 59

-Population genetics is the study how the gene pool of a population changes over time, leading to a species evolving.

Answer 60

Freq of G= number of copies of allele G in population divided by total number of copies of the gene G+g in the population

Answer 61

Single nucleotide polymorphism (SNP- pronounced SNIPS) is a point mutation (single base G, C or A T) in a segment of DNA that occurs in more than 1% of the population

Answer 62

-SNPS are important genetic markers that are currently used to distinguish individuals and to identify things such as disese succeptibility in individuals. -A genetic marker can be defined as an identified sequence of DNA at a locus on a chromosome

Answer 63

-A genome-wide association study (GWAS) rapidly scans SNP markers across the genomes of individuals with a known disease or disorder to compare them to control individuals -Significant differences in allele frequency caused by SNPs are the first step in identifying cause and effect relationship between a SNP and a disease or disorder -Once a link is made, scientists look to develop better treatments and diagnostic and prevention strategies. -GWAS have identified DNPs related to conditions including cancer, diabetes, heart disease, mental illness, Parkinsons, Crohns and Alzheimer’s

Answer 64

For a diploid gene with two alleles (B and b) at frequencies p and q, the frequency of genotypes BB, Bb and bb will be p2, 2pq and q2 These frequencies sum to one; hence: p2 + 2pq + q2 = 1

Answer 65

The process of determining the precise order of nucleotides within a segment of a gene on a chromosome It includes any method or technology used to determine the specific order of adenine, guaninine, cytosine and thymine in a strand of DNA

Answer 66

Involves the testing of highly variable regions of an individual’s DNA that contain short repeating sequences called STRs located in the introns -The exact number of STRs varies from person to person because we inherit DNA from our parents, DNA profiles can be used to confirm how closely related individuals are, trace inheritance patterns, and solve crimes

Answer 67

PCR is a technique used to exponentially amplify large numbers of copies of a specific sequence of DNA -The central paradigm to PCR is understanding that: All life contains genetic material that is unique to a species and individuals within a species contain unique genetic sequences -As a result, PCR amplifies unique DNA sequences of any organism that can be shared to other nucleotide segments of a known source -Used for genetic testing, medical diagnosis, DNA fingerprinting

Answer 68

-Genetic sequencing is the process by which the exact sequence of nucleotides in a chromosome or gene is determined -Special versions of the four nucleotides called chain-terminating, nucleotides are each labelled with a different colored fluorescent marker -During PCR cycles different length DNA fragments will form due to the chain-terminating nucleotides stopping further sequencing.

Answer 69

-The application of genetics to preserve species through maintaining variation within populations so that they are capable of coping with environmental change -Scientists analyze alleles of multiple genes to examine the genetic diversity within a species

Answer 70

-The ecological threshold that indicates the smallest number of individuals in a species or population capable of surviving in the wild for an ongoing amount of time -Small populations are more susceptible to genetic drift than large populations -This occurs when differential breeding leads to the loss of alleles from the gene pool due to the small number of individuals carrying particular alleles

Answer 71

Cheetahs have very low levels of genetic variation This is due to two significant population bottlenecks: the last ice age and 1800s onwards Pre-Genetic screening: Captive breeding programs had high mortality rates All modern cheetahs descended from a bottleneck

Answer 72

-An international effort to decode the entire sequence of the human genome -A complete and accurate sequence of 3 billion DNA base pairs- an estimate 20,000 to 25000 genes have been identified

Answer 73

-A technique that separates the double stranded DNA of two species into single strands -The single strands form each species are mixed and allowed to bind -They are then reheated and the temperature of separation is recorded -The more closely related the species, the stronger the hybridization, the higher the temperature required to separate the hybrid DNA= a more recent ancestor -African chimpanzees and humans

Answer 74

Cytochrome C is a highly conserved mitochondrial protein found in all eukaryotic organisms. It is involved in energy production (ATP) -International mass spectrometry studies have been used to determine the amino acid sequence of Cytochrome C across multiple species -IN more than thirty species 37 of the 104 amino acids are conserved (identical at that position)

Answer 75

-Comparative genomics uses computer based analysis to compare the genome sequences of different species -Results are used to study evolutionary relationships, conserved DNA sequences which indicate genes that are essential to life -Genomic similarities and differences provide scientists with a better understanding of how the appearance and behavior of organisms has changed over time.