Brainscape's Knowledge GenomeTM

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


See full index

Science Summer Review (Before grade 10/grade 10 level) > Genetics > Flashcards

Genetics Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What does DNA stand for?

A

Deoxyribonucleic acid

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

What is DNA?

A

A molecule found in living things which contain the instructions that make species unique.

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

When is DNA passed onto offsprings?

A

DNA is passed from adult organisms to their offsprings during reproduction.

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

Where is DNA found in prokaryotes vs eukaryotes?

A

In eukaryotes, including animals, plants and fungi, DNA is found inside a special area of the cell called the nucleus. There is also a small amount found in the mitochondria from the female parent.

In prokaryotes, it is found floating in the nucleoid region

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

What does a mitochondria do?

A

Generate the energy the cell needs to function properly.

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

How does DNA appear? (general)

A

Each DNA molecule is tightly packaged into a “squished” form called a chromosome

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

When does DNA unwind/uncoil?

A

DNA uncoils so it can be copied. DNA also unwinds so that its instructions can be used to make proteins during translation.

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

How does inheritance work? (How much of DNA comes from each parent)

A
  • In sexual reproduction, organisms inherit half of their nuclear DNA from the male parent and half from the female parent.
  • Each parent contributes one sex chromosome.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is DNA made of

A

DNA is made of building blocks called nucleotides. These building blocks are made of 3 parts:

  1. Ribose (sugar)
  2. Phosphate
  3. Nitrogen base

Ribose (sugar) and Phosphate make up the backbone.

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

What is the complete set of DNA like for humans?

A

The complete set of DNA, or genoma, for a human contains about 300 billion bases and about 20,000 genes (groups of bases whose letters create a protein) on 23 pairs of chromosomes.

(Summary: 300 billion bases, around 20,000 genes, 23 pairs of chromosomes)

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

How big is a gene (in bases)?

A

The size of a gene may vary greatly, ranging from about 1,000 bases to 1 million bases in humans.

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

How much of the DNA sequence do genes make up?

A

Genes only make up about 1% of the DNA sequence. The remaining 99% regulates when, how and how much of a protein is made.

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

Who discovered DNA?

A

The Swiss biochemist Frederich Miescher first observed DNA in the late 1800s. But nearly a century passed from that discovery until researchers unravelled the structure of the DNA.

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

Who uncovered the structure of proteins? (Name and jobs)

A

Linus Pauling was a chemist, engineer, peace activist, author, and educator who has been called one of the 20 greatest scientists of all time.

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

What was Linus Pauling awarded? (Awards, catagories, and years)

A

For his scientific work, Pauling was awarded the Nobel Prize in Chemistry in 1954. For his peace activism, he was awarded the Nobel Peace Prize in 1962.

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

What was Linus Pauling only one of five to do, and who were the others?

A

He is one of only five people to have won more than one Nobel Prize (the others being Marie Curie, John Bardeen, Frederick Sanger, and Karl Barry Sharpless).

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

How did Linus Pauling uncover the structures of proteins?

A

Pauling worked on uncovering the structures of proteins and his approach using X Ray Crystallography and model building inspired the work of Rosalind Franklin, Watson and Crick.

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

How did scientists figure out the double helix?

A

The importance of DNA became clear in 1953 thanks to the work of Rosalind Franklin, James Watson, and Francis Crick. By studying X-ray diffraction patterns and building models, the scientists figured out the double helix structure of DNA.

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

What is the DNA structure?

A

Scientist use the term “double helix” to describe DNA’s winding, two-stranded chemical structure.

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

What does DNA look like?

A

The sides of the ladder as strands of alternating ribose and phosphate groups. Each “rung” of the ladder is made up of two nitrogen bases, paired together by hydrogen bonds.

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

What nitrogen bases pair?

A

Adenine and Thymine, Cystosine and Guanine

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

Why is DNA structured the way it is?

A
  • DNA’s unique structure allows the molecule to copy itself during cell division.
  • When a cell prepares to divide, the DNA helix splits down the middle and becomes two single strands.
  • These single strands serve as templates for building two new, double-stranded DNA molecules - each a replica of the original DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the steps for specialization?

A
  • Humans start as a fertilized egg called a zygote, which divides to make more and more cells.
  • These cells are stem cells which are not yet specialized and can become any kind of body cell.
  • DNA is transcribed into mRNA to make proteins.
  • The area of DNA which is “read” (transcribed) determines the specialization of the cell.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What else can influence how DNA is read?

A

External factors, like temperature, can also determine which parts of the DNA are read

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why are stem cells important in medicine?

A
  1. They can allow for regrowth of various parts of damaged tissue and organs
  2. They are essentiel for advancing research into disease mechanisms and the development of new treatments.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are some ethical issues in the use of stem cells?

A
  1. Results in the demise of the embryo
  2. Stem cells from another person’s organs/tissues carry risk of rejection.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is asexual reproduction?

A

Creating a carbon copy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What makes a good observation? (2 things to avoid/do)

A
  • Avoid assumptions
  • Be concise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How does the sex of an offspring develop?

A
  • The default sex chromosome is female as a gonad, but if you have the SRY gene on the Y chromosome, the release of testosterone occurs, and you develop male.
  • Newly fertilized zygotes develop without indication of sex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is Klinefelter syndrome?

A
  • 47 chromosomes
  • 0.1 - 0.25% of males affected
  • There is no exact cause
  • Women who get pregnant after 35 are more likely to have a child with it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is Turner syndrome?

A
  • 45 chromosomes
  • 0.04% of females
  • Most women with it are 4 foot 3, shorter than average
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is XYY syndrome?

A
  • 47 chromosomes
  • 0.1% of males affected
  • associated with an increased risk of learning disabilities and delayed development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is Trisonomy X?

A
  • 47 chromosomes
  • 0.1% of females
  • delayed development likely
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the problems with a binary sex system for humans? (Suggest a solution)

A
  • Does not account for the biological diversity that occurs such as those who are intersex
  • Does not recognize the spectrum of gender identities, which can lead to discrimination and marginalization.
  • Could result in inappropriate or harmful medical interventions and legal challenges for those who aren’t male or female assigned and identifying.
  • A solution could be catagories based on testosterone level ranges
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

4 functions of DNA?
(End of lesson 1)

A
  • DNA stores the genetic instructions for the development and functioning of living organisms.
  • DNA replicates itself to ensure that genetic information is passed on during cell division.
  • DNA is transcribed into RNA, which is then translated into proteins that perform various functions in the cell.
  • DNA can mutate, leading to genetic variations that drive evolution and adaptation in species.

Replication, encoding information, mutation or recombination, and gene expression

36
Q

What are proteins?

A

Proteins are long chains of amino acids which are folded into 3D structures and are shaped specifically for their task, much like a key is shaped to work for a specific lock.

37
Q

What are proteins needed for?

A

Proteins are needed for the structure, function, and regulation of the body. For example, they are used to make muscle, hair, and tissue. They are also important as enzymes and chemical messengers. Proteins also make antibodies, which protect the body from invading disease.

38
Q

What is the function of antibodies protein?

A
  • battle bacteria and viruses that make us sick
  • attach to invading microbes and mark for destruction
39
Q

What is the function of androgen and estrogen protein?

A
  • control genes that trigger the onset of puberty in males and females
40
Q

How are proteins made?

A

The synthesis of proteins takes two steps: transcription and translation.

Transcription takes the information encoded in DNA and encodes it into mRNA, which heads out of the cell’s nucleus and into the cytoplasm.

Translation uses the mRNA, a ribosome, and tRNA to synthesise proteins from amino acids.

41
Q

How does transcription work?

A

The DNA molecule partially unwinds so that the gene can be transcribed. This “unzipping” of the DNA is done by the enzyme helicase.

Next, an enzyme called RNA polymerase lines up nucleotides to create a complementary strand of messenger RNA (mRNA). Since mRNA is a single-stranded molecule, only one of the two strands of DNA is used as a template for the new RNA strand.

After transcription, the new RNA strand is released from the nucleus and the two unzipped DNA strands bind together again to form the double helix.

42
Q

How does pairing work for RNA?

A

The new strand of RNA is made according to the rules of base pairing:

DNA cytosine pairs with RNA guanine

DNA guanine pairs with RNA cytosine

DNA thymine pairs with RNA adenine

DNA adenine pairs with RNA uracil

Every three base pairs on the mRNA is called a codon

43
Q

How does translation work?
(What is the first phase - A site)

A
  • In translation, an mRNA chain is sent to the cytoplasm, where it binds with ribosomes
  • The start codon AUG enters the ribosome’s A site, and a tRNA with a specific amino acid binds according to the mRNA sequence.
  • Each tRNA consists of many nucleotides, with three forming an anticodon that pairs with complementary mRNA bases.
44
Q

How does translation work?
(What is the second phase - P site)

A
  • The ribosome now slides down the mRNA, so that the tRNA in the A site moves over to the P site, and a new codon fills the A site.
  • The tRNA molecule whose anticodon is complementary to the mRNA in the A site attaches bringing the amino acid with it.
  • A PEPTIDE bond is formed between the amino acid attached to the tRNA in the A site and the amino acid that is now in the P site.
45
Q

What are the 3 codons for stop?

A

UAA, UAG and UGA

46
Q

What is the difference between DNA, mRNA, tRNA, and RNA

A

DNA: The molecule that stores genetic information in cells.

mRNA: The molecule that carries genetic instructions from DNA to ribosomes for protein synthesis.

tRNA: The molecule that brings amino acids to ribosomes to build proteins.

RNA: A molecule that helps in various genetic processes, like carrying instructions (mRNA) and building proteins (tRNA).

47
Q

How is hereditary information passed on from one generation to the next?

A

Genes are specific sequences of nucleotides that code for particular proteins. Through the processes of meiosis and sexual reproduction, genes are transmitted from one generation to the next.

48
Q

Who discovered dominant and recessive traits and how?

A
  • Augustinian monk named Gregor Mendal crossed a yellow and green pea plant
  • He called the yellow dominant because it ‘won’

-The new plants did asexual reproduction and got plants that were both green and yellow. Since the green colour had been hidden in the plants before he called it recessive.

  • Mendel believed that factors pass from parents to their offspring, but he did not know of the existence of DNA.
49
Q

What are alleles?

A
  • Modern scientists know that genes are composed of (segments of DNA molecules that control discrete hereditary characteristics) called alleles.
  • Homozygous mean both alleles are the same
  • Heterozygous mean both alleles are different
  • The pair of alleles is called the genotype
  • The visible characteristic that we see is called the phenotype
50
Q

What are genome’s?

A

The set of all genes that specify an organism’s characteristics is known as the organism’s genome . The genome for a human cell consists of about 20-30,000 genes. The gene composition of a living organism is its genotype.

51
Q

What are diploid cells?

A

Most complex organisms have cells that are diploid. Diploid cells have a double set of chromosomes, one from each parent.

In a diploid cell, there are two genes for each characteristic. In preparation for sexual reproduction, the diploid number of chromosomes is reduced to a half, or haploid.

52
Q

What are haploid cells?
End of lesson 2

A

Haploid cells are gametes, or sex cells, and they are formed through meiosis. When two gametes come together in sexual reproduction, their combination produces a new diploid cell, in which the offspring receive a gene of each type from each parent

53
Q

What is a mutation and what causes them?

A

A change in the structure of a DNA sequence, often resulting in variation.

They can arise from errors during DNA replication or cell division. They can happen to cells due to exposure to mutation causing agents (mutagens) such as cigarette smoke, UV light, or X-rays.

54
Q

What is a gene mutation?

A

A gene mutation results when the specific order of the A, G, C, and T bases that make up a particular gene changes, affecting only a single gene.

Types include:
Deletion - One base is missing
Addition - One extra base is added
Substitution - One base is substituted for another

55
Q

What is a gene mutation that benefits an organism?

A

Changes in the sequence of DNA bases may produce proteins that could be beneficial to an organism.

These types of mutation are known as positive mutations.

56
Q

What is a gene mutation that harms an organism?

A

Changes in the sequence of DNA bases may produce proteins that could be harmful to an organism. These types of mutation are known as negative mutations.

57
Q

What is a gene mutation that doesn’t benifit or harm an organism?

A

Most often, errors in the base sequence of DNA appear to have no effect on the organism. These types of mutations are called neutral mutations.

58
Q

What is a chromosomal mutation?

A

A chromosomal mutation occurs when pieces of a chromosome or an entire chromosome are misplaced. These changes often occur during MITOSIS. They affect many genes in the chromosome and change the PROTEINS made by those genes.

(Just like gene mutations, chromosome mutations may be beneficial, have no effect, or be harmful to an organism depending on which protein(s) it impacts)

59
Q

What are the types of CHROMOSONAL mutations?

A

Deletion - Chromosome segment is lost

Translocation - Piece of a chromsome transfers to another

Duplication - Piece of one chromosome goes to it’s PAIR or HOMOLOGOUS CHROMOSOME

Inversion - Part of a chromsome is flipped.

60
Q

What causes cancer?

A

Cancer is caused by several mutations that occur in the cell cycle, causing cells to reproduce out of control. This results in large, deformed cell masses called tumors.

61
Q

How do cancer cells differ from other cells?

A

A cancer cell is different than a normal body cell in several ways:

Cancer cells often have too many or too few CHROMOSOMES.

Cancer cells can produce chemical messages that tell the body to provide it with nutrients which takes away nutrients from the healthy cells

Cancer cells reproduce very quickly, as often as every 24 hours.

62
Q

What happens if a tumor is:
undetected?
not cancerous?
cancerous?
cancerous & spreading?

A

If a tumor goes undetected, pieces can break off and move through the blood stream, landing elsewhere in the body and starting new tumors.

If a tumour is not cancerous and not spreading, it is benign.

If a tumour is cancerous, it is called MALIGNANT.

If a malignant tumour is spreading, it is said to have METASTISIZED

63
Q

What does environment mean?

A

Conditions in which something lives.

64
Q

What does adaption mean?

A

Characteristic that helps an organism live in its enviornment.

65
Q

What is natural selection?

A

Natural selection is the process in which heritable physical traits (phenotypes) are selected for by natural factors .

Factors include:
Climate change, predators, and disease

People who have physical traits that are harmful to survival (such as no resistance to a new disease) die, while those people who have beneficial physical traits (such as resistance to a new disease), survive and pass on their traits to their offspring.

66
Q

What are mutations most often?

When do positive ones happen most often?

A

Mutations are usually neutral and do not offer much benefit. Most mutations that are beneficial to an organism’s survival tend to happen during the creation of the egg/sperm, before the organism is even born.

67
Q

How have humans done artificial selection in the past?

A

Humans have been breeding plants and animals for tens of thousands of years. Through this process, they have been able to choose to mate animals that have desired phenotypes.

This process of human-lead selection of
heritable traits is called ARTIFICIAL SELECTION.

68
Q

What are Genetically Modified Organisms?

A
  • A GMO is an organism or microorganism whose genetic information has been altered to contain a segment of DNA from another organism.
  • Modern RECOMBINANT DNA technology enables the “stitching together” of pieces of DNA from different plants and animals.
69
Q

What are the concerns surrounding GMOs?

A
  • GM crops have been planted extensively for a little over a decade.
  • While no negative health consequences have been detected (or are anticipated), the relative newness of GM crops requires that we continue to monitor for health impacts.
  • At present, the ecological concerns that stem from the way GM crops are planted are a more pressing concern.
70
Q

What are the pros (3) and cons (2) of GMO’s?

A

Pros:
- Can survive better (eg. resist bugs due to bad taste)
- food has favourable qualities (eg. healthier, bigger, tastier)
- Uses less chemicals

Cons:
- If all of the crop are nearly genetically identical, a single disease could wipe them all out
- Potential for unwanted allergic reactions

71
Q

_______ enzymes are like…

What is recombinant DNA?

A
  • All organisms on Earth use DNA and that DNA is the same regardless of what living being it is taken from.
  • As a result, DNA from different organisms can be “cut and pasted” together, resulting in RECOMBINANT DNA.
  • RESTRICTION enzymes are like “molecular scissors” that cut DNA at specific sequences.
    The cut ends can be joined together and into a continuous DNA strand by DNA LIGASE.
72
Q

What is cloning?

A

Cloning describes a number of different processes that can be used to produce GENETICALLY IDENTICAL copies of a living thing. The copied material, which has the same genetic makeup as the original, is referred to as a clone.

73
Q

What does Bt toxin do?

A
  • Produces a toxin that kills the larvae (caterpillars) of certain insects that are pests.
  • The gene that produces Bt toxin is introduced into such plants by recombinant DNA technology, and results in the selective killing of crop-feeding insects.
74
Q

What are natural clones in nature? (excluding mamals)

A

In nature, many plants and bacteria produce genetically identical offspring through a process called asexual reproduction. In asexual reproduction, a new individual is generated from a copy of a single cell from the parent organism.

75
Q

What are natural clones in humans and mamals?

A
  • In humans and other mammals who reproduce sexually we can also get clones (twins).
  • Twins are produced when a fertilized egg splits, creating two or more copies that carry almost identical DNA.
  • Identical twins have nearly the same genetic makeup as each other, but they are genetically different from either parent.
76
Q

What is a pro and con of sexual and asexual reproduction?

A

Sexual
Pro - increases diverstiy
Con - Requires a partner

Asexual
Pro - only 1 parent required
Con - low genetic diversity

77
Q

What is the gene cloning type of artificial cloning?

A
  • Gene/DNA/Molecular cloning produces copies of genes or segments of DNA.
  • Researchers use gene cloning to make copies of genes they wish to study.
  • The procedure consists of inserting a gene from one organism, often referred to as FOREIGN DNA, into the genetic material of a carrier called a VECTOR.

(Examples of vectors include bacteria and viruses.)

  • After the gene is inserted, the vector is placed in laboratory conditions that prompt it to multiply, resulting in the gene being copied many times over.
78
Q

What is the reproductive cloning type of artificial cloning.

A
  • Reproductive cloning produces copies of whole animals.
  • In reproductive cloning, researchers remove a mature somatic cell from an animal that they wish to copy.
  • They then transfer the DNA of the donor animal’s somatic cell into an egg cell, that has had its own DNA containing nucleus removed.
  • The egg develops till it is an embryo, then is implanted into the womb of an adult female, who gives birth to an animal with the same genetic makeup as the one who donated the SOMATIC cell, the clone
79
Q

What is the therapeutic cloning type of artificial cloning.

A
  • Therapeutic cloning produces embryonic stem cells for experiments.
  • The DNA is removed from an unfertilized egg, the cells are fused, it becomes a closed embryo, and results in embryonic stem cells
80
Q

Why is it more difficult to clone humans and other primates than mammals?

A
  • One reason is that two proteins essential to cell division, known as spindle proteins/fibers, are located very close to the chromosomes in primate eggs.
  • The removal of the egg’s nucleus to make room for the donor nucleus also removes the spindle proteins, interfering with cell division.
81
Q

Why do clones not always look identical?

What is the application of reproductive cloning?

A
  • Clones do not always look identical . Although clones share the same genetic material, the enviornment and mutation can play a big role in how an organism looks.
  • Reproductive cloning may enable researchers to make copies of animals with the potential benefits for the fields of medicine and agriculture.
82
Q

What else could we use cloning for?

A
  • Use clones to create larger populations of food animals
  • Use close to recreate extinct species
  • Use clones to recreate dead pets for families
  • Use clones to grow organs, blood, or bone marrow for people who need transplants
83
Q

Problems with Cloning?

A

INCREASE in birth size (PAY ATTENTION, COMMON SENSE IS OPPOSITE)

  • Defects in vital organs, such as the liver, brain and heart
  • Premature ageing*
  • Problems with the immune system.
84
Q

Why would clones created from a cell taken from an adult have a shorter lifespan?

A
  • As cells go through their normal division, the tips of the chromosomes, called TELOMERE, shrink.
  • Over time, the telomeres become so short that the cell can no longer divide and the cell dies.
  • This is part of the natural ageing process.
  • Clones created from a cell taken from an adult might have chromosomes that are already shorter than normal, which may condemn the clones’ cells to a shorter life span.
85
Q

Which types of cloning are accepted, which are not?

A
  • Gene cloning is a carefully regulated technique that is largely accepted today and used routinely in many labs worldwide.
  • However, both reproductive and therapeutic cloning raise important ethical issues, especially as related to the potential use of these techniques in humans.
86
Q

What is a pro and a con for reproductive and therapeutic cloning?

A

Pro - Stem cells can cure diseases

Con - Shorter lifespan, unknown longterm effects

Science Summer Review (Before grade 10/grade 10 level) (4 decks)

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