Biology: Grade 9. Science IB: Revised Flashcards
Biotechnology: What are GMO’s?
A genetically modified organism is a living organism whose genetic material has been modified by introducing new genes into its DNA, in order to obtain new characteristics.
Benefits of GMO’s
List 5
- Resistant to pesticide
- Decrease global warming
- Better crops
- Crops containing more nutritional value
- Medical studies
Concerns with GMO’s
List 4
- Messing up the food chain (overpopulation or extinction of a species)
- Cross-pollination
- Profit driven by GMO compagnies
- Can be used by the wrong people
What is assisted reproduction?
Help in the union of…
Assisted reproduction represnet all medical procedures that help in the union of an ovum and a spermatozoon for the purpose of achieving fertilization.
What is the purpose of assisted reproduction?
Deeveloped to help infertile couples conceive a child.
What is infertility?
A term used to describe a couple inability to conceive a child after one year of sexual relations.
Causes for infertility:
- Poor quality of gametes
- Poor quantity of gametes
- Malformations of the reproductive system
- Malformations of the reproductive system cause by STBBI’s
List the 4 types of assisted reproduction IN ORDER!
- Hormonal treatments
- Artificial insemination
- In-Vitro Fertilization
- Intracytoplasmic sperm injection
How do hormonal treatemnts work?
Conflict: what can this result in.
Subject takes hormone-based drugs that can help trigger ovulation. Taking hormones can often cause the ovaries to produce more than one ovum per cycle, which can result in multiple pregnancies.
How does artificial insemination work?
If you forget, when… as well as how etc.
Introduction of spermatozoa directinly into the uterus of a woman.
- Done during ovulation
- Uses a catheter
- Fertilization occurs in the fallopian tubes and pregnancy then takes its natural course.
How does in-vitro fertilization work?
- Ova and spermatozoa are fertilized in the labratory
- The embryos obtained are transplanted into the woman’s uterus to continue developement
- Treatement is recommended when fallopian tubes are block or artificial insemination attempts have failed.
How does intracytoplasmic sperm injection work?
- Forces sprematozoa into ovum
- Used when not enough sperm cells are available for fertilization
1. Ova are collected
2. Sperotozoa are injected into ova
3. Ova are inserted into ovum
4. Embryos are implanted in uterus
Benefits of assited reproduction:
List 4
- Sterile couples can reproduce
- It might become free?
- Allows people who are single to conceive a child
- Allows homosexual couples to conceive a child
Concerns of assited reproduction:
- It can be expensive
- Ethical conflicts regarding disposing of embryos
- Chances of multiple carriges
- Success rates are average
What is mitosis?
Mitosis is a type of cell division used to make identical copies of cells.
Mitosis is a cell division that results in…. ___________ ___________ daughter cells.
- Two
- Identical
In mitosis the daughter cells each contain ____ ____ chromosomes.
- twenty-three
- Pairs of
Function/Purpose of mitosis:
- Growth and repair of damaged tisses
- (Replacement of dead blood cells)
- (Repairement of cuts, fractures, muscel etc.)
Neurons are the only cells incapable of dividing or repairing themselves
What are the 5 steps in the process of Mitosis?
- DNA coils up into chromosomes and nuclear membrane dissolves
- Chromosomes duplicated (DNA replication) and centrioles moves towards the poles
- Chromosomes line up in the center of the cell. Spindle fibers attach to the center of the cell and the other half to the opposite pole of the cell
- The spindle fibers pull have the chromosome pair to one pole and the other half to the opposite pole of the cell
- The cell membrane pinches off in the center to give rises to two new cells (cytokinesis). Chromonsome decondenses and nuclear membrane form. The result is 2 identical daughter cells, each containing 23 pairs of chromosomes.
What is meiosis?
Produces …. #
They are also called ________ what does this term refer to
Meiosis is a type of cell division that produces four different cells that are genetically different from the original mother cell. Reproductive cells are also called gametes; sperm cells (spermatozoa) and egg cells (ova) that unite during fertilization.
Meiosis in females happens in the _____ (in the _____) and _____ (____) are only mature enough to be fertilized starting at _______
- Uterus
- in the womb
- egg cells
- ova
- puberty
Meiosis in males starts at ____ in the ____ and continues until _____.
- Puberty
- Testicles
- Death
Each ….. produced during meiosis contains only …… chromosome(s) of each …. so they can combine during fertilization to produce a ……. ……… of chromosomes
- daughter cell
- one
- pair
- complete
- Pair
What does DNA stand for?
Deoxyribonucleic acid
Where do you find DNA
In the nucleus of each cell. Found in all LIVING organisms.
DNA contains:
The genetic code of the organism. This code is based on the code from that organisms parents.
DNA is shaped like…
A double helix
The side of the DNA ladder that twists to form a double helix are made of
2 different types of nucleoyides; a sugar and a phosphate group. These molecules alternate.
The steps of the DNA ladder is…
A line of nitrogen bases
How many nitrogen bases are there?
4: Adenine, Guanine, Thymine, Cytosine.
Each DNA ladder step is made of ……. …….. that connect with eachother in the ………. . Base ….. only connects with ………. and base …… only connects with ………
- Two bases
- middle
- A
- T
- C
- G
What is a gene?
A gene is a segment of DNA that determines a specific genetic characteristic.
How are genes passed on?
Genes are passed on through heredity.
What is our entire set of genes called?
Our entire set of genes is called the human genome.
All members of a species…..
Have almost the sames genes. This determines wether we are mammals, insects, amphibians, plant, viruses, etc.
Do differences exist across members of the same species?
Yes! Small differences exist across members of the same species, giving them unique traits. This explains why we aren’t all identical.
What is a chromosome?
A chromosome is a structure that contains DNA (genes) of an organism. When a cell is dividing, DNA coils up and forms a chromosome. Each DNA molecule in the nucleus of a cell is a chromosome.
How many chromosome exist in the nucleus of each cell? Excluding reproductive cells.
The nucleus of each cell (excluding reproductive cells) contains 23 pairs of chromosomes for a total of 46 chromosomes.
Which chromosomes are the same/different in men and women?
There are 22 chromosomes that are similar for both men and women, however the 23rd chromosome is a pair of sex chromosomes. Women have 2 X chromosomes whereas men have an X chromosome and a Y chromosome.
What does a karyotype show?
A karyotype shows the chromosomes of an individual, displayed from largest to smallest.
What is cell culture?
Cell culture is a process by which cells are reproduced outside the organism they come from.
What can cell cultures do?
- We can cultivate cells like bacteria (unicellular) and plant and animal cells (multicelluar).
- Cell cultures are done to better understand how cells work.
- test medications and beauty products, reducing the need for animal testing
- Develop vaccines
- Create tissues like skin to treat burns
How do cell cultures work?
When a tissue is extracted…
1. scientists seperate targeted cells
2. Depending on the type of cell cells are put in test tubes, flasks, and petri-dishes to cultivate
3. Containers are filled with a liquid or a solid medium that contains the conditions needed to allow the cell to thrive: Must be maintained, also, temp. humidity, pH etc.
This allows the cells to grow and reproduce properly.
Must be done in a sterile environment, anti-biotics can be added
What are tissues?
When embryos develop, cells that are similar divide and form a tissue. A tissue is a set of identical or different cells that work together to preform a common function in an organism.
Name the 4 types of tissues
- Epitheal tissue
- connective tissue
- Muscle tissue
- Nerve tissue
Define epithelial tissue:
This tissue lines the outer surfaces of the body and the inner surfaces of organs.
Define connective tissue:
This tissue protects, supports and connects other tissues.
Define muscle tissue:
This tissue is made up of elongated cells that can contract.
Nerve tissue:
This tissue is made up of neurons.
What are organs?
Several tissues combine to form organs. An organ is a different part of an organism that performs one or more specific functions.
What is a system?
Organs combine to form systems. A biological system is a set of cells, tissues and organs that perform one or more common functions.
