Brainscape's Knowledge GenomeTM

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


See full index

Biology Chapter 3 > Chapter 3 > Flashcards

Chapter 3 Flashcards

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

Type of cells

A

Eukaryotic and prokaryotic cells

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

Organelles in eukaryotic cells

A

Mitochondion, Nucleus, Nucleolus, ROugh Endoplasmic Reticulum, Ribosome, Call surface membrane, Smooth Endoplasimc reticulum, Golgi appratus, Lysosome, Centrioles

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

Organelles in Procaryotic cells

A

Ribosome. circular DNA, cell surface membrane , cell wall , cytoplasm , flagellum , pili, capsule, plasmid, infoloding cell surface membrane

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

Common features between the cells of living organishms

A

Cell surface membrane, cytoplasm, DNA, ribosome

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

Function of mitochondria

A

It is the site of aerobic respiration within eukaryotic cells. IT is surrounded by a double membrane with the inner membraine folded to form structures called cristae. It produces ATP from respiration.

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

Function of Ribosome

A

It is the site of translation. Each ribosome is a complex of ribosomal RNA and proteins. 80s ribosomes are found in eukaryotic cells and 70s ribsomes are found in prokaryotes, mitochondra and chloroplasts

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

Two types of endoplasmic enticulum

A

The two types are : Rough Endoplasmic Reticulum (rER) and Smooth Endoplasmic Reticulum (sER)

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

Function of rER

A

rER is formed from fols of membrane contious with the nuclear envelope. The surface of rER is covered with ribsomes and the role of it is to process proteins made on the ribsomes

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

Function of sER

A

sER is also formed from folds of membrane but its function is distince from the rER, being involved in the production of processing and storage of lipids, carbohydrates and steriods. ( IT DOES NOT HAVE ANY RIBOSOMES ON THE SURFACE)

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

Function of the golgi appratus

A

It consists of flattened savs of membrane similar in apperance to the smooth endoplamic reticulum. The role of the Golgi appratus is to modify proteins and lipids before packagin them into golgi besicles. The vesicles then transport the proteins and lipis to their required destinations.

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

Funtion of lysosome

A

Lysosome are the specialist forms of vesicle which contain hydrolytic enzymes. The role of it is to break down wast materials such as worn out organelles.

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

Function of centrioles

A

Centroles are made of hollow fibers knows as microtubules. It is the filaments of protein that can be used to move substances around insie a cell as well as to support the shape of a cell from the inside. Two contrioles at right angles to each other form a centrosome which oraganises the spindle fibers during cell division ( THEY ARE NOT FOUND IN PLANTS OR FUNGI)

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

Organelles included in the process of protein synthesis

A

Nucleus ( transcription of the DNA code occurs here), ribsomes ( free ribsomes and those on the rER produce proteins in the process of translation, rER, Golgi appratus, Cell surface membrane ( proteins formed within the cell are secreted here)

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

Process of Protein synthesis

A

-The nucleolus manufacture ribsome for protein synthesis in the rER.
-The nucles manufacutes mRNA, which is needed by ribsomes to make proteins.
-The ribosomes in the rER make proteins.
-The rER processes the proteins which are then sent in vesicles to the golgi body
-The golgi body further processes the proteins and sends them in vesicles to the plasma membrane.
-The besicles fuse with the plasma membrane to secrete the finished protein product.

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

Differences between eukaryotic and prokaryotic cells

A

Plasmids, capsules, flagellum, pili, mesosomes

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

Description of plasmid

A

Small loops of DNA that are seperate from the main circular DNA molcules. Plamids contain genes that can be passed between prokaryotes. ( NOT PRESENT IN ALL PROKARYOTES)

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

Description of capsule

A

Dome prokaryotes are surrounded by a final outer layer knows as a capsule. This is sometimes called the slime capsule. It helps to protect bacteria from drying out and from attack ny cells of the immune system of the host organism. (NOT PRSENT IN ALL PROKARYOTES)

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

Description of flagellum

A

A long hair like structure that rotaes, enabling the prokaryote to move. Dome prokaryotes have more than one. (NOT PRSENT IN ALL PROKARYOTES)

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

Description of pili

A

Thread like structures on the surface of some bactera that enable the bacteria to attach to other cells or surfaces

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

Description of Mesosomes

A

Infolded regions in the plasma membrane of some prokaryotic cells. They have many fucntions including aerobic respiration, cell wall formation and DNA replication

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

Description of Circular DNA

A

The genetic material of prokaryotic cells mainly consists of a single circular strand of DNA that is not contrained in a membrane bound nucleus. The area in the prokaryotic cell where this circular DNA molcule is found is knows as the nucleiod.

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

Description of Ribosomes

A

Prokaryotic ribosome are 70s ribsomes and are smaller than the 80s ribosomes of eukaryotic cells. They are the site of protein synthesis in prokaryotic cells

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

The phases of cell cycle

A

Interphase. NUclear division ( mitosis), cell division ( cytokinesis)

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

Interphase phases

A

It consists of three phases : G1 phase, S phase, G2 phase

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

What happen during the three phases

A

During G1 phase, a signal is received telling the cell to divide again. The DNA in the nucleuse replicates resulting in each chromosome consisting of two identical sister chromatids.
During S (synthesis) phses, the cells make the RNA, enzymes and other proteins required for growth during the G1 phases.
During G2 phase, the cell continues to grown and the new DNA that has been synthesised is checked and any error are repaired.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is cytokinesis

A

It is after mitosis phses. Once the nucleus has divided into two genetically identical nuclei, the whole cell divisdes and one nuclus moves into each cell to create two genetically identical daughter cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is mitosis

A

It is the porcess of nuclear division by which two genetically identical daughter nuclei are produced that are also genetically identical to the parent cell nucleus.

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

What are the four stages of mitosis

A

Prophase, Metaphases , Anaphase , Telophase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What happens during prophase

A

Chromosomes condense and are not visible when stained. The chromosome consist of two identical chromatids called sister chromatids that are join at the centromere. The two chromosomes move towards opposite poles. The pindle fibres begin to emerge from the centrosomes. The nuclear envelope breaks down into small vesicles.

30
Q

What happens during Metaphase

A

Centrosomes reach opposite poles
Spindle fibres (protein microtubules) continue to extend from centrosomes
Chromosomes line up at the equator of the spindle (also known as the metaphase plate) so they are equidistant to the two centrosome poles
Spindle fibres (protein microtubules) reach the chromosomes and attach to the centromeres
Each sister chromatid is attached to a spindle fibre originating from opposite poles

31
Q

What happen during anaphase

A

The sister chromatids separate at the centromere
Spindle fibres begin to shorten
The separated sister chromatids are pulled to opposite poles by the spindle fibres

32
Q

What happen during telophase

A

Chromosomes arrive at opposite poles and begin to decondense
Nuclear envelopes begin to reform around each set of chromosomes
The spindle fibres break down

33
Q

Uses of Mitosis

A

It helps replace worn out cells and tissues. It also help in growth in multicellular organisms. Again in Asexual reproduction.

34
Q

Sperm functions

A

Sperm have flagellum that allow them to swim toward the egg cell. They have also contain mitochondria which provide them with energy for mobility. It has acrsome in the head which contain digestive enzyme which break down the zona pellucida allowing the sperm to fertilise together with the eegg cell

35
Q

Egg cell function

A

They are much larger than the sperm cell as they contain food to nourish a growing embryo. It has follicle cells that form a protective coating and have a jelly-like gylcoprotein layer known as zona pellucide that forms an impenetrable barrier after fertilistion, preventing any other sperm from entering the egg.

36
Q

Process of fertilisation

A

1) The sperm reach the ovum
2) Chemicals are released from the cells surrounding the ovum, triggering the acrosome reaction.
3) The acrosome swells, fusing with the sperm cell surface membrane.
4) Digestive enzymes in the acrosome are released
5) The enzyme digest through the follicle cells..
6) … and the zona pellucide surrounding the ovum
7) THe sperm fuses with the ovum membrane
8) The spem nucleus enters the ovum
9) Enxyme relased from lusomes in the ovum thicken the jelly-like layer, preventing entry of other sperm.
10) Nuclei of the ovum and sperm fuse

37
Q

What is meiosis

A

It gives rise to cells that are gentically different from each other and is the type of cell division used to procuce gamates.

38
Q

What are the two round of division in meiosis

A

Meiosis I and meiosis II

39
Q

What happen during meiosis

A

The homologus pairs of chromosomes are spilt up, to produce two hapliod nuclie.

40
Q

What happen during meisosi II

A

During meiosis II. the chromatids that make up each chromosome sepreate to produce four hapliod nuclei.

41
Q

What are two genetic combination alleles.

A

Crossing over and independent assortment

42
Q

What is crossing over

A

Crossing over is the process by which non-sister chromatids exchange alleles

43
Q

THe process of crossing over

A

During meiosis I homologous chromosomes pair up and are in very close proximity to each other.The paired chromosomes are known as bivalents.The non-sister chromatids can cross over and get entangled.These crossing points are called chiasmata.The entanglement places stress on the DNA molecules.As a result of this, a section of chromatid from one chromosome may break and rejoin with the chromatid from the other chromosome

44
Q

What is independent assortment

A

Independent assortment is the production of different combinations of alleles in daughter cells due to the random alignment of homologous pairs along the equator of the spindle during meiosis I

45
Q

What is stem cell

A

A stem cell is a cell that can divide (by mitosis) an unlimited number of times

46
Q

What are three types of potency

A

Totipotency, pluripotency, and multipotency

47
Q

What is totipotnecy

A

Totipotent stem cells are stem cells that can differentiate into any cell type found in an embryo, as well as extra-embryonic cells (the cells that make up the placenta and umbilical cord). The zygote formed when a sperm cell fertilises an egg cell is totipotent, as are the embryonic cells up to the 16-cell stage of human embryo development

48
Q

What is pluripotency

A

Pluripotent stem cells are embryonic stem cells that can differentiate into any cell type found in an embryo but are not able to differentiate into cells forming the placenta and umbilical cord

49
Q

What is multipotency

A

Multipotent stem cells are adult stem cells that have lost some of the potency associated with embryonic stem cells and are no longer pluripotent

50
Q

Why are stem cells used in stem cell medicine

A

teSm cells have the ability to differentiate into other specialised cell types, they are very valuable in medical research and treatments as they have the potential to replace damaged tissues and cells (that result from certain diseases)

51
Q

What are two cources of human stem cells used in medicine

A

Embryonic stem cells and adult stem cells

52
Q

The use of embroyonic stem cells

A

They have the potential to differentiate to almost any type ot cell making them suitable to be used in medicine. The embryos used for research are often the waster embroyos from IVF treatments. This causes ethical issues as the embroys have the potential to develop into human being.

53
Q

The use of adult stem cells

A

They can only be differentated into alimited range of cell types. They are collected form the bone marrow and brain. It is a less controvertial issue compare to embroyonic stem cells due the consent givien when the stem cells are collected.

54
Q

The tasks carried out by the regulatory authorities

A

Reviewing proposals for scientific research that uses stem cells and deciding if this research should be allowed to go ahead
Licensing and monitoring of research centres that are involved in stem cell research
Providing guidelines and codes of practice for stem cell researchers to ensure they are working to the same high standards
Monitoring developments in scientific research into stem cell therapies
Providing governments and other professional bodies with correct, up-to-date advice and information on stem cell research, which in turn helps society to understand how stem cells are being used and why this work is important

55
Q

The processes of cell differentiation

A

Under certain conditions, some genes in a stem cell are activated, whilst others are inactivated
mRNA is transcribed from active genes only
This mRNA is then translated to form proteins
These proteins are responsible for modifying the cell (e.g. they help to determine the structure of the cell and the processes that occur within the cell)
As these proteins continue to modify the cell, the cell becomes increasingly specialised
The process of specialisation is irreversible (once differentiation has occurred, the cell remains in its specialised form)

56
Q

What is Operons

A

A cluster of structural genes that are transcribed together (these code for useful proteins e.g. enzymes)
Control elements, including a promoter region (a DNA sequence that RNA polymerase initially binds to) and an operator region (where transcription factors bind)
Some operons may include regulatory genes that code for activators or repressors

57
Q

What is lac operon

A

Structural genes in prokaryotes can form an operon: a group or a cluster of genes that are controlled by the same promoter
The lac operon found in some bacteria is one of the most well-known of these
The lac operon controls the production of the enzyme lactase (also called β-galactosidase) and two other structural proteins

58
Q

What are the components of lac operon

A

Promoter for structural genes
Operator
Structural gene lacZ that codes for lactase
Structural gene lacY that codes for permease (allows lactose into the cell)
Structural gene lacA that codes for transacetylase

59
Q

The binding sit of lac repressor protein

A

It has two binding sites that allow it to bind to the operator in the lac operon and also to lactose (the effector molecule)

60
Q

When lactose is absent

A

The regulatory gene is transcribed and translated to produce lac repressor protein
The lac repressor protein binds to the operator region upstream of lacZ
Due to the presence of the repressor protein RNA polymerase is unable to bind to the promoter region
Transcription of the structural genes does not take place
No lactase enzyme is synthesized

61
Q

When lactose is present

A

There is an uptake of lactose by the bacterium
The lactose binds to the second binding site on the repressor protein, distorting its shape so that the repressor protein cannot bind to the operator region
RNA polymerase is then able to bind to the promoter region and transcription takes place
The mRNA from all three structural genes is translated
The enzyme lactase is produced and lactose can be broken down and used for energy by the bacterium

62
Q

What is epigenetic

A

Epigenetics is the control of gene expression by factors other than an individual/s individual sequence
It involves the switching-on and switching off of genes without actually changing the actual genetic code.

63
Q

There are two ways to alter gene expression

A

Methylation of DNA and Histone modification

64
Q

DNA methylation

A

Methyl group (CH3) is directly added to DNA to cytosine bases which influence the gene expression. Methylation of DNA supresses the transcription of the affected gene by inhibiting the binding of transcription factor and enymes needed for transcription.

65
Q

What is phenotype

A

Phenotype is the observalbe charachteristcs of an organism

66
Q

Phenotype variation can be explained in two ways

A

Gentic factors and environment factors and it can also be done by both

67
Q

How environmental factor can effect phenotype

A

Diet, growing conditions

68
Q

Continuous variation

A

Continuous bariation occurs when there are quantitive differences in the phenotype of indiciduals within a population for particular charactiertics

69
Q

Discontnuous variation

A

Qualitative differences in the phenotype of indiciduals within population give rise to discontinuous varitaion

70
Q

Causes of continuous variation

A

Some phenotype are affected by multiple different fenes or by multiple alleles for the same gene at many different loci.

Biology Chapter 3 (1 decks)

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