MIDTERMS Flashcards
(109 cards)
1
Q
During which phase of the meiotic cell cycle does dna replication occur
A
INTERPHASE
2
Q
When does crossover take place in meiosis
A
PROPHASE
2
Q
During which phase of meiosis does the nuclear membrane reform around chromosomes?
A
TELOPHASE II
3
Q
A human cell containing 22 autosomes and a Y chromosome is
A
SPERM CELL
3
Q
Meiosis II is similar to mitosis in that..
A
because both processes involve the separation of sister chromatids, leading to the formation of two daughter cells from a single parent cell.
4
Q
Homologous chromosomes move towards opposite poles of a dividing cell during…
A
MEIOSIS I
In the second stage of meiosis (meiosis II), the sister chromatids are then separated, resulting in four haploid cells.
5
Q
Metaphase of meiosis I and meiosis II differ in that…
A
METAPHASE I: homologues line up
METAPHASE II: duplicated chromosomes line up. no longer homologous pairs.
6
Q
Asexually reproducing organisms produce offspring that are genetically identical to each other
and to the parents. What type of cell division are the offspring a product of?
A
MITOSIS
This process involves duplicating the cell’s chromosomes and then splitting them equally into two new nuclei, resulting in two daughter cells that are genetically identical to the original parent cell.
6
Q
Which of the following correctly ranks nucleic acid structures in order of size, from smallest
to largest?
A
nucleotide, codon, gene, chromosome
7
Q
At which stage of meiosis do chromatids separate and become daughter chromosomes?
A
ANAPHASE II
Anaphase I: begins when homologous chromosomes separate. The nuclear envelope reforms and nucleoli reappear. The chromosomes coil up, the nuclear membrane begins to disintegrate, and the centrosomes begin moving apart.
7
Q
The process in which haploid gametes are formed in diploid organisms is called:
A
MEIOSIS
8
Q
A human cell containing 44 autosomes and two X chromosomes is…
A
Somatic cell of a female
8
Q
Independent assortment is one of the factors that contributes to genetic diversity. Independent assortment is associated with which stage of meiosis?
A
METAPHASE I
9
Q
The fertilized egg (zygote) of a human contains how many chromosomes?
A
46
10
Q
Which cells of the human body are made through the process of meiosis?
A
GAMETES
11
Q
What 2 cells would be more genetically similar to each other?
A
two somatic cells produced by the same person
Somatic cells are all the cells in the body except for germ cells (sperm and egg cells).
11
Q
His meticulous experiments with pea plants in the mid-19th century laid the foundation for our understanding of heredity. “Father of Genetics”
A
GREGOR MENDEL
Used pea plants (Pisum sativum) due to their distinct, observable traits
Focused on seven characteristics:
1. Seed shape
2. Seed color
3. Flower color
4. Pod shape
5. Pod color
6. Flower position
7. Plant height
11
Q
The term ‘synapsis’ is associated with which process?
A
CROSSING OVER
11
Q
A ____ is the complete set of chromosomes of an organism, arranged and
displayed in pairs and ordered by size.
A
KARYOTYPE
A karyotype is a visual representation of an organism’s complete set of chromosomes, typically arranged in pairs and ordered by size, from largest to smallest.
11
Q
If a diploid organism has a genome consisting of 22 chromosomes, its gametes will have how many chromosomes.
A
11
12
Q
When does DNA replication occur during meiosis?
A
INTERPHASE I
13
Q
Crosses examining a
single trait
A
Monohybrid Cross
Experiments
14
Q
Crosses examining two
traits simultaneously
A
DIHYBRID CROSS
14
Q
In a pair of alleles, one is dominant and its traits are expressed in the organism, while the other is recessive and its traits are masked in the presence of the dominant allele.
A
LAW OF DOMINANT
15
Each organism **carries two alleles** for a given trait, **one inherited from each parent**.
LAW OF SEGREGATION
15
3 LAWS OF INHERITANCE
1. LAW OF SEGREGATION
2. LAW OF INDEPENDENT ASSORTMENT
3. LAW OF DOMINANCE
16
Alleles of different genes **assort independently during gamete formation**.
This means the inheritance of one **trait is generally not affected by the inheritance of another**, leading to **genetic variation.**
LAW OF INDEPENDENT ASSORTMENT
17
refers to the inheritance of traits
controlled by a **single gene with two
alleles,** one of which may be
completely dominant to the other. The
pattern of inheritance of simple traits
depends on whether the traits are
controlled by genes on autosomes or
by genes on sex chromosomes.
MENDELIAN INHERITANCE
18
* is the fundamental **physical and functional unit of heredity**
* are **composed of segments of DNA**, the molecule that encodes genetic information in cells.
* Some act as instructions to produce molecules called **proteins**, and many of them do not apparently encode.
GENES
19
is one of two or more **versions of DNA sequence** (a single base or a segment of bases) at a given genomic location. An individual inherits
two alleles, one from each parent, for any given genomic location where such variation
exists.
**ALLELE**
19
2 TYPES OF ALLELE
**Recessive** - The allele that is
expressed when paired with a
recessive allele
**Dominant** - The allele that is
expressed when paired
with a dominant allele
20
Traits **controlled by genes on the sex chromosomes** are
called
X- LINKED TRAITS
20
a diagram that shows the occurrence and appearance or phenotypes of a particular gene or organism and its ancestors from one generation to the next. It is a presentation of **family information summarized in a chart** using a standardized set of symbols.
PEDIGREE CHART
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* affected individuals have at least one affected parent
* the phenotype generally appears every generation
* two unaffected parents only have unaffected offspring
* no carriers
AUTOSOMAL DOMINANT
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* the phenotype can skip generations
* two unaffected parents can have affected offspring
* have carriers
AUTOSOMAL RECESSIVE
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* **All daughters** of a male who has the trait will also have the trait.
* There is **no male to male transmission**; the trait follows the inheritance of the X-chromosome.
* Sons can have the trait only if their mother also has the trait.
* Same inheritance pattern as autosomal dominant traits in human females.
X- LINKED DOMINANT
23
* The trait is more **common in males** than in females.
* If a **mother has the trait, all of her sons should also have it.**
* There is no male to male transmission.
* It has the same inheritance patterns as autosomal recessive for human females.
* The son of a female carrier has a 50 percent chance of having the trait.
* Mothers of males who have the trait are either heterozygous carriers or homozygous and express the trait.
X- LINKED RECESSIVE
23
* Trait expression and transmission is **only in males**, the individuals with the **Y chromosome**.
* If a male has a trait, so should his father and paternal grandfather as well as his sons and their sons. It follows the inheritance of the Y chromosome.
Y- LINKED
24
a **chart** that allows you to easily determine the
**expected ratios of possible genotypes**
in the offspring of two parents. The
mating between two parents is called
a cross.
PUNNETT SQUARE
## Footnote
developer, British geneticist:
**Reginald C. Punnett.**
24
Forms:
1. **Nervous system** (brain, spinal cord, peripheral nerves)
2. **Epidermis** (outer layer of skin)
3. **Hair, nails, and teeth**
4. **Lens of the eye and inner ear**
5. **Neural crest cells** (which give rise to various tissues like pigment cells, cartilage, and bone in the face)
6. **PITUITARY GLAND**
7. **JAWS AND TEETH**
8. **GERM CELLS**
**ECTODERM**- OUTERMOST LAYER
24
Forms:
1. **Muscles** (skeletal, smooth, and cardiac)
2. **Bones and cartilage**
3. **Blood and blood vessels**
4. **Kidneys and ureters**
5. **Connective tissues** (like cartilage and bone)
6. **Spleen**
7. **Dermis** (inner layer of skin)
8. **Internal sex organs**
9. **Skeleton**
10. **Heart**
11. **Adrenal cortex**
**MESODERM**-MIDDLE
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* **DIGESTIVE ORGANS**
* **RESPIRATORY TRACT (LUNGS, BRONCHI)**
* **Liver and pancreas**
* **Thyroid and parathyroid glands**
* **Bladder and urethra**
| DRLTB
**ENDODERM**- INNER
26
3 MAIN REASONS FOR MITOSIS
**1. GROWTH
2. REPAIR/ HEALING
3. ASEXUAL REPRODUCTION**
27
CELL DIVISION BY **MITOSIS**
**EMBRYO, EPITHELIAL CELL, INTESTINAL CELL**- CELLS THAT DIVIDE CONSTANTLY
**SPINAL CORD, CARDIAC CELL, BRAINCELL/ NERVE CELL-** CELLS THAT DIVIDE RARELY OR NEVER
28
2 KINDS OF CELL DIVISION
1. **MITOSIS**- Division of somatic cells (muscle cell, skin cell, bone cell, nerve cell)
2. **MEIOSIS**- Creation of new sex cells
29
a body cell' a cell whose genes will **not be passed on to future generations**
SOMATIC CELL
30
A cell that is **destined to become a gamete** (egg or sperm cell); a cell whose genes can be passed on to future generations.
GERM CELL
31
A cell with **2 chromosome sets** in each of its cells; all body somatic cell
DIPLOID (2N)
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A cell with **1 chromosome set** in each of its cells; all gametes (sperm, egg)
HAPLOID (N)
33
- A diploid cell will give rise to a diploid cell
- Chromosome number **remains the same**
- The DNA remains **identicaly the same**
- One cell (2n) give rise to two cells (2N)
CHARACTERISTICS OF **MITOSIS**
34
Process of **growth, development, and reproduction**
**CELL CYCLE**
most of the cycle is called ***INTERPHASE***
35
**Longest phase** in cell cycle
**INTERPHASE**
36
**3 stages of interphase** are called:
**G1**- Growth
**S (DNA synthesis)**- Growth and DNA replication
**G2**- Growth and final preparation for division
37
* During ____ nucleus of **cell divides**, forming two nuclei with **identical information**
- Produces **two genetically identica**l cells
Definition: Type of cell division that result in two dauther cells having the **same number and kind of chromosomes**as the present nucleus
MITOSIS
38
the process where a cell's cytoplasm **divides after nuclear division** (mitosis or meiosis), resulting in **two daughter cells. **
*Division of cytoplasm*
CYTOKINESIS
39
ANIMAL VS. PLANT MITOSIS
ANIMAL CELL
* Centriole and aster **present**
- Daughter cells separated by **cleavage furrow**
PLANT CELL
* **No visible** centriole or aster
- Separated by **cell plate**
40
fibers that are **made out of microtubules**
SPINDLES
41
ENSURE THAT THE SEPARATION OF THE SISTER CHROMATIDS GOES WELL
SPINDLE FIBERS
42
A type of cell division that result in
-**Four** dauther cells
-each with **half the number of chromosomes** of the parent cell
- production of **gametes**
MEIOSIS
## Footnote
TWO DIMENSIONS; MEIOSIS I AND MEIOSIS II
43
RESULT OF MEIOSIS
* **Gametes** ( egg and sperm form)
* **Four haploid cells** (n) with **one copy of each chromosomes**
* **One allele of each gene**
* **Different combinations** of alleles for **different genes** along the chromosomes
44
A **human embryo** a about ____ after conception shows development of distinctive features
7 weeks
| 1mm
45
Biologist use ____ to **study development,** chosen for the ease with which they can be **studied in laboratory**
**MODEL ORGANISMS**
46
The **formation of a diploid zygote from a haploid egg and sperm**
FERTILIZATION
47
It is **triggered when the sperm meets the egg** and the **tip** of the sperm **releases hydrolytic enzymes** that digest material surrounding the egg
ACROSOMAL REACTION
48
**Gamete contact** and/ or **fusion depolarizes** the egg cell membrane and sets up a _____
**fast block to polyspermy**
48
The **fertilization envelope** acts as the:
**Slow block to polyspermy**
48
**Fusion of egg and sperm** also initiates the:
**CORTICAL REACTION**
| High concentration of **Ca² + ions** in the egg
49
is a crucial process in mammalian fertilization where sperm, after ejaculation, undergo a series of **biochemical and physiological changes,** making them capable of binding to and penetrating the egg's outer layer (zona pellucida) and ultimately fusing with the egg's membrane.
Capacitation
49
Sperm travel through an outer layer of cells to reach the ____ the **extracellular matrix of the egg**
**ZONA PELLUCIDA**
50
In mammals the **first cell division** occurs ________ hours after sperm binding
12- 36 hours
## Footnote
the diploid nucleus forms after this first division of the zygote
51
a period of **rapid cell division without growth**
It partitions the cytoplasm of one large cell into many smaller cells called **blastomeres**
The **blastula** is a ball of cells with fluid filled cavity called **blastocoel**
CLEAVAGE
52
**COMPLETE DIVISION OF THE EGG**, OCCURS IN SPECIES WHOSE EGGS HAVE LITTLE OR **MODERATE AMOUNTS OF YOLK**, SUCH AS SEA URCHINS AND FROGS
**HOLOBLASTIC CLEAVAGE**
53
**INCOMPLETE DIVISION** OF THE EGG, OCCURS IN SPECIES WITH **YOLK- RICH EGGS**, SUCH AS REPTILES AND BIRDS
**MEROBLASTIC CLEAVAGE**
54
The process by which cells **occupy their appropriate locations**
**MORPHOGENESIS**
* **Gastrulation**- movement of cells from the blastula surface to the interior of the embryo
* **Organogenesis**- formation of organs
54
* The **formation of organs**
* Various regions of the germ layers develop into rudimentary organs
* Early vertebrate organogenesis, the _ forms from mesoderm, and the neural platr forms from ectoderm
**Organogenesis**
-**Notochord**
54
# Gastrulation in **humans**
**Cluster of cells** at one end of the blastocyst
**Inner cell mass**
| **Human eggs have very little yolk**
54
* **movement of cells from the blastula** surface to the interior of the embryo
* Rearrage the cells of blastula into three layered embryo, called **gastrula**
**GASTRULATION**
* Embryonic **germ layers**
1. Ectoderm
2. Endoderm
3. Mesoderm
*it contributes to specific structures in the adult animal*
55
In human Gastrulation it is the **human equivalent of the blastula**
BLASTOCYST
| HUMAN EGGS HAVE **VERY LITTLE YOLK**
56
**outer epithelial layer of the blastocyst** and does not contribute to the embryo, but instead **initiates implantation**
**Trophoblast**
57
-Begins at the **vegetal pole** of the blastula
-**Mesenchyme** cells migrate into blastocoel
- Vegetal plate forms from the remaining cells of the vegetal pole and buckles inward through **invagination**
Gastrulation in **Sea Urchins**
57
# Gastrulation in **Sea Urchins**
The **newly formed cavity** is called the:
This opens through the ____ which will become the **anus**
* Archenteron
* blastopore
57
- Begins when a group of cells on the **dorsal side** of the blastula begins to ivaginate
- This **forms a crease** along the region where the **grey crescent formed**
Gastrulation in **Frogs**
58
# Gastrulation in **Frogs**
The **part above the crease** is called: ____ of the blastopore
**Dorsal lip**
59
are specialized tissues that **surround and support the developing embryo**, providing protection and facilitating nutrient and waste exchange, and include the amnion, chorion, allantois, and yolk sac.
## Footnote
These **enclose specialized structures outside of the embryo**
**Extraembryonic membranes**
60
* Prior to gastrulation, the embryo is composed of an **upper and lower layer**, the **epiblast** and **hypoblast**, respectively
- During gastrulation, **epiblast cells move toward the midline of the blastoderm** and then into the embryo toward the yolk
Gastrulation in **chicks**
60
# Gastrulation in **chicks**
The **midline thickens** and is called the:
**Primitive steak**
60
This gastrulation involves the **inward movement from the epiblast, through a primitive steak**, similar to the chick embryo
**Human** Gastrulation
61
Embryos are **surrounded by fluid** in a sac called the:
## Footnote
Mammals and reptiles including birds are called **AMNIOTES** for this reason
**amnion**- This **protect the embryo** from desiccation and allows reproduction on dry land
62
**Four extraembryonic membranes** that form around the embryo
1. **Chorion functions**- Gas exchange
2. **Amnion**- Enclose the amniotic fluid
3. **Yolk sac**- enclose the yolk
4. **Allantois**- Dispose of waste products and contributes to gas exchange
63
**Early vertebrate organogenesis**, the _ forms from mesoderm, and the neural platr forms from ectoderm
**Notochord**
63
# Identification:
1. The neural plate soon curves inward, forming the:
2. The neural tube will become the central nervous system:
3. It develop along the neural tube of vertebrates and form various parts of embryo(nerves, parts of teeth, skull bones)
4. Mesoderm lateral to the notochord forms blocks called:
5. Lateral to somites the mesoderm splits to form the coelom:
1. **Neural tube**
2. **Brain and spinal cord**
3. **Neural crest cells**
4. **Somites**
5. **Body cavity**
64
# True or false
Organogenesis in the chicks is quite **different** to that in the frog
False
* **SIMILAR**
65
# True or false
The **mechanism of organogenesis** in invertebrates are *similar*, but the **body plan** is *very different*
TRUE
66
Refers to the resulting **specialization** in structure and function
**Differentiation**
66
Is the term used to describe the process by which cell or group of cells becomes **committed to a particular fate**
**Determination**
67
**Programmed Cell Death** is also called:
**apoptosis**
## Footnote
extra neurons are **removed** by apoptosis
68
embryonic cells in the limb bud respond to positional information indicating **location along three axis**:
| PAD
1. Proximal- distal axis
2. Anterior- posterior axis
3. Dorsal- Ventral axis
| PAD
69
# The ***organizer***
They **transplanted tissues between early gastrulas** and found that the transplanted dorsal lip **triggered** a second gastrulation in the host
Spermann and Mangold
| **Dorsal lip**- Organizer
69
The **first two balstomeres of the frog** embryo are:
**TOTIPOTENT**- Can develop into all possible cell types
| last until 8 cell stage
69
Acts as **cytoplasmic determinants**, fixing germ cell fate at the earliest stage of development
**P granules**
69
He **performed experments** to determine a cells developmental potential ( range of structures to which in can give rise)
**Hans Spermann**
70
Cells in a **multicellular share the same genome**
**Differences** in cell types are the result of the **expression of different sets of genes**
Read
71
**Diagrams** showing organs and other structures that arise from each region of an embryo
**Fate Mapping**/ **Fate maps**
72
Mesoderm tissue under the ectoderm where the **posterior side of the bud is attached to the body**
**Zone of polarizing activity** (ZPA)
73
**Inductive signal** for limb development
**Sonic hedgehog**
74
Also **play roles during the limb pattern formation**
Hox genes
75
Is essential for **proper specification** of cell fate in human embryo
Ciliary function
75
Play roles in **left-right specification**
**Motile cilia**
76
Play roles in **normal kidney development**
**Monocilia** (nonmotile cilia)
