The reason that there are Okazaki fragments during DNA replication is ultimately because:A) Some parts of the chromosome are made of RNA and different polymerases have to be used B) Polymerases can only synthesize in the 5' to 3' direction C) There are only enough dNTP's to support quick replication on one strand, so the other strand lags behind it D) It is necessary to "slow down" one of the strands so that replication does not occur before cells have a chance to grow
B) Polymerases can only synthesize in the 5' to 3' direction
The leading strand's directionality is 3' to 5', so polymerase has no problem with replicating this one. But the lagging strand has the opposite directionality, so the polymerase must work in the opposite direction of the replication fork.In consequence, the replication process undergoes periodic breaks, and the enzymes have to stop and start again while helicase separates both strands, resulting in the polymerization of okazaki fragments.
The food web for a particular ecosystem is shown below.Greenhopper Gras Duck Ant Lizard Frog Tadpole Snake Sunlight Algse Bacteria Decayed Matter Earthworm What would most likely happen i the grasshopper population had a major increase? A. The frog population would decrease. B. The snake population would increase c. The duck population would decrease, D. The lizard population would not change.
The snake population would increase.
Just had the question
When natural waters become overloaded with plant nutrients, such as nitrates and phosphates, they become _______________.
Eutrophication is defined as the when natural water becomes overly enriched with nitrates and phosphates containing fertilizers, and detergents which induced excessive amount of algae in water. The process of eutrophication may result in water body oxygen depletion.
Example of eutrophication are algal bloom, and great increase of phytoplankton population which increased levels of nutrients in water body.
Polyester will absorb KOH True False
Explanation: Polyester is hydrophobic. For this reason, polyester fabrics don't absorb perspiration, or other fluids, leaving the wearer with a moist, clammy feel. Polyester fibers typically have a low level of wicking. Relative to cotton, polyester is stronger, with a greater ability to stretch
Steve has had a stroke and comes to you for follow-up today. On examination you find that he has increased muscle tone, some involuntary movements, an abnormal gait, and a slowness of response in movements. He most likely has involvement of which of the following? A) The corticospinal tract B) The cerebellum C) The cerebrum D) The basal ganglia
D) The basal ganglia
Basal ganglia is located at the base of forebrain and the top of midbrain. It is involved in many functions because it is connected to many parts of the brain like thalamus and cerebral cortex. One of the functions of basal ganglia is to control the voluntary movements of the skeletal muscles.
Damage to basal ganglia can disturb the muscles causing involuntary movements, abnormal gait and increased muscle tone. For example, muscle tone is the tension in skeletal muscles caused due to minor involuntary contractions. Substantia nigra part of basal ganglia is responsible for controlling it. If it is damaged, muscle tone can increase which will cause unnecessary tension in skeletal muscles leading to uncontrolled movements.
Give 3 examples of other organ systems in the human body.
nervous system, skeletal system, muscular system, cardiovascular system, urinary system and respiratory system are just a few
All systems with short explanation
Circulatory system / Cardiovascular system:
Circulates blood around the body via the heart, arteries and veins, delivering oxygen and nutrients to organs and cells and carrying their waste products away.
Keeps the body's temperature in a safe range.
Digestive system and Excretory system:
System to absorb nutrients and remove waste via the gastrointestinal tract, including the mouth, esophagus, stomach and intestines.
Eliminates waste from the body.
Influences the function of the body using hormones.
Integumentary system / Exocrine system:
Skin, hair, nails, sweat and other exocrine glands
Immune system and lymphatic system:
Defends the body against pathogens that may harm the body.
The system comprising a network of lymphatic vessels that carry a clear fluid called lymph.
Enables the body to move using muscles.
Collects and processes information from the senses via nerves and the brain and tells the muscles to contract to cause physical actions.
Renal system and Urinary system
The system where the kidneys filter blood to produce urine, and get rid of waste.
The reproductive organs required for the production of offspring.
Brings air into and out of the lungs to absorb oxygen and remove carbon dioxide.
Bones maintain the structure of the body and its organs.
Which structure is located in the nucleus of the cell?